US1213037A - Photographic-printing apparatus. - Google Patents

Description

I. E. THORNTON.

PHOTOGRAPHIC PRINTING APPARATUS.

APPLICATION FILED JUNE 8.1915.

WITNEssEs.

J. E. THORNTON.

PHOTOGRAPHIC PRINTING APPARATUS.

APPLICATION FILED JUNE 8,1915.

Patented Jan. 16, 1917.

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J. E. THORNTON.

PHOTOGRAPHIC PRINTING APPARATUS.

APPLICATION FILED JUNE 8,|9l5 Patented Jan. 16,

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WITNESSES E. THORNTON.

PHOTOGRAPHIC PRINTING APPARATUS.

APPLICATION FILED JUNE 8,1915. l1,21 3,037. PatentedlJan. 16,1917.

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APPLICATION FILED JUNE 8,1915. Patented Jan. 16,1917.

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APPLICATION FILED JUNE 8.1915.

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J. E. THORNTON.

PHOTOGRAPHIC PRINTING APPARATUS.

APPLICATION FILED JUNE 8,1915.

1,21 3,037. Patented Jan. 16,1917.

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INVENTOR WITNEssEs 7 l STATES PATENT oEmoE,

JoHN EDWARD THORNTON, or WEsT nAnrsrEAD, LoNDoN, ENGLAND, AssIGNon To JOHN oWDEN OBRIEN, or MANCHESTER, ENGLAND.

A:PHOTO(irRAEHIC-PRINTIN'G APPARATUS.

vSpecification of Letters Patent.

Patented J an. 16, 1917.

Applicafion filed J une 8, 1915. Serial N o. 32,949.

To all whom z't may. concern.'

Be it known that I, JOHN EDWARD THORN- TON, a British subject, residing at lVest Hampstead, London, England, have invented certain new and useful Improvements in Photographic-Printing Apparatus, of which the following is a specification.

This invention relates to the printing of cinematograph films (or other continuous strips such as post card paper) coated with an emulsion of low sensitiveness, such as those prepared with bichromate 0r iron salts.

In order to make the features of this invention clear, I will first describe the state of the art up to the most recent advance. Practically all the known methods of nrinting films of .low sensitiveness (such as bichromate) at a rapid rate are those comprised in my prior applications Serial No. 733,632, filed November 26, 1912 and Serial 4No. 745,725, filed February 1, -1913, and

Letters Patent No. 1,158,587 ,"dated'November4` 2, 1915 granted to,` me; and the Whole series of such apparatus and methods differ extensively from what are suitable for printing films Jof high sensitiveness- (suchas silver). In the present state of 4knowledge of the art the methods are' so different that the apparatus suitable for one system is useless for the other. In silver printing the pictures are printed througha picture gate or aperture of a size to exposefone, two, or more adjacent pictures at aitimef, upon film that has been previously perforated. 4These perforations are used as the means-f0rfeed-- ing the film through the printing` machine with a step-by-step motion,`"and the exi posures are made intermittently-bja,shutjter, which passes light through--thegate orf aperture while the film strijlisatfrest and intercepts the light while the"`film"is shifted a step forward. The exposure '.is very short- (generally about a quarter of a second) and the intermittent vmovement of the film very rapid. A silver printing machine runnmg at a .normal rate will make about 8000 shift.

it is not intermittently shifted, there is no this invention are z-(l) shutter Cutting off the iight intermittenuy, and ,the film 1s not perforated before printmg. On the contrary a very large number of pictures (generally about 500) are ex posed simultaneously, the film strip'is moving continuously forward during the whole p eriod of exposure, it is exposed to a fixed light of labout 6000 candle power for a pcrlod of about 4 minutes, and the perforations have to be made after the lm is printed, developed and dried. This method of perforatlon -is absolutely necessary, because of the difference in length between the two strips of film (negative film and sensitive film) 1n a length of so many pictures. Without such system of perforating after printing, whereby the positions of the perforations are adjusted and placed to suit the relatlve positions of the pictures, it would lbe impossible to secure sufficiently accurate of low sensitiveness (such as bichromate) to obviate the loss of time occasioned in ur nt orders by having to make the perforations afterqprinting and drying was finished, instead of before. (2.) To find some satisfactory means of -insuring accurate register .when re-printing two, three or more images superimposed upon each other for multicolor work. This result can be secured (if the film is perforated beforehand) by using In printing film` the perforations as means for' registering,

but cannot be done if there are no perforations. (3) While meeting the conditions ofl and 2 to also insure about as large an output per machine per hour .from film of low sensitiveness (such as bichromate) regularly obtained upon film of high sensitiveness (such as silver), although bichromate film requires approximately about 500 times as much exposure as silver These results are obtained lby the followin combination, worked out as indicated 1n this specification :-(a) By retaining the principle of exposing a large number of pictures simultaneously to a fixedv light, as in previous bichromate methods. (b) By substituting perforated for unperforated film. (c) By substituting intermittent film movement, and intermittent light by means of intermittent shutter, for the previously used `continuous film movement, continuous light,

and no shutter. (d) By introducing a loop or slack length (which may belong or short) between simultaneously printed pictures, so that no two adjacent pictures are allowed vto print at the same exposure stroke, in

order that those that are printed at the same time may each be independently placed and adjusted by registering pins or sprockets, each to its own correct position independently of any other. (e) Or by forming a film loop between each exposure or printing position, such loop having a length in picture spaces equal to theY number of printing positions plus one over, the object of such loop being to provide sufficientv lm to contain as many pictures as there are printing spaces plus one, so that as the film is advanced one complete loop at every stroke each different picture impression is printed on `a different loop, so that by the time the film has passed completely through the machine every space in every loop is filled with a printed impression, no part of the film being presented .I a second time to the light, and no double impressions made. (f) The same loop may be used for the purposes stated in paragraphs (d) and (e) although the functions of each are different. (g) By introducing a grid of vertical leaves, placed between the stationary light and stationary film, in

5 order that all spreading light rays may be converted into perpendicularly acting ones such grid being given a continuous movement during exposure, in order to prevent its image from being impressed upon the film. By combining these features in one unit apparatus and using a mercuryl lamp of'about 6000 candle power an output of about 500 to 600 feet an hour of bichromate film can be printed the pictures appearing on the strip in progressive order and correct sequence.

The present invention is' therefore designed to provide apparatus by which ready perforated lms of low sensitiveness, such as bichromate, can be printed, in which accurate registration of the successive printings, single exposures of-the pictures, a sufficiently long exposure, and a sufliciently i rapid rate of production to be of commercial value are all secured.

The invention consists essentially in an apparatus for printing the film simultaneously at a number of points throughout its length-a single picture being exposed at eachand drawing forward after each exposure or each alternate exposure a length of film vequal to the number of pictures printed-and in the particular disposition or arrangement of apparatus therefor; comprising a mercury vapor lamp or lamps; a bed, roller, or other carrier for the films; a shutter to cut off light from the film during its forward traverse; a moving grid to cause the light rays to strike the film perpendicularly: means for providing a loop or slack in the films between the points of exposure; and sprocket wheels, claws or other lneans for registering the perforations in the films and drawing them forward intermittently. l

The invention will be Afully described with reference to the accompanying drawings, ,in which various forms of carrying out the invention are shown in diagrammatic section.

Figure l. Sectional elevation of apparatus withr two mercury vapor lamps-of the Cooper Hewitt type-placed end to end, with printing bed parallel to the longitudinal axis of the lamp, a short slack length of film between each printing point, and a longslack length or loop of film between each lamp, alternate pictures being printed by the two lamps. Fig. 2. Sectional elevation of similar apparatus, with a single lamp, printing beds at both sides of the lamp, short slack lengths of film between, each printing point, and a long slack length or loop of film at one end to permit of the film traveling from one side of the lamp toV the other to print the alternate pictures. Fig. 3. Sectional elevation of apparatus similar to Fig. 2, showing the printing of two films simultaneously. Figs. 4 and 5. Sectional elevation and plan of similar apparatus, showing a high candle power mercury vapor lamp of the quartz type, and theA film falling into a slack loop between the printing/points. Fig. 6. Sectinalelevation vapor lamp of Cooper Hewitt type andthe film passing over a. series of rollers, at each of which a spaceis printed, and falling into a long loose half twisted loop between ythe printing points. Figs. 7 and 8. Longitudinal and transverse sectional elevations of similar apparatus. showing mercury vapor lamps of Cooper Hewitt type, the film passingover top and bottom rollers parallel with the longitudinal axis of the lamp and falling into a long loose loop between the printing points. l Figs. 9, l0 and 11; Vertical section, front elevation and plan of similar apparatus with a' number of lamps placed between two flat beds, and 'transversely to the direction of travel of the film, with rollers or bobbins over which the film is carried in a spiral. Fig. 12. Sectional elevation of similar apparatus, with a single lamp placed' transversely of the travel of the film, a number of rollers grouped around it to present a corresponding number of printing points around the lamp, the film being carried in A adjacent picture spaces of the films, at va number of points throughout the length of the lms, simultaneously to the action of a lsuitable printing lamp, and then intermittently 'draw forward the v'films to similarlyT their movement.

lstration, these sprockets should havethe expose an equal number of non-adjacent picture spaces, but always in such order that no picture space is presented more than once to the exposing lamp. A bed is mounted 1on a suitable Jframe or standard, upon or against which the sensitive film and the negative film are caused to travel.' During exposure, the negative and' sensitized films must be clamped together very closely to insure sharply defined prints, which is effected by movable clamping plates, or by putting a pulling tension on the films by any sultable tension device, preferably pneumatic suction. I y

- vIn Fig. 1 a simple form of the apparatus is shown' with two lamps B B' of the Cooper Hewitt type set end to end and dividedinto two parts with 'a space or gap between them. It comprises a flat bed 'C upon which the films A and A' are held during exposure to the light from the lamp B and over which they larel caused to traverse; a clamping plate D, capable of moving to and from the bed A with exlposure aperture (l, by which the "films are firm y and immovably held during exposure; a reciprocating grid -E to cause the light rays to strikethe film perpendicularly; and lsprocket wheels G tov engage the perforations of the films to draw them forward at -fintervals as required. The sprocket wheels G, to engage' the perforations in the lmargins of the films, are mounted along both sides of the flat bed plate C, and are geared together to, synchronize in To insure accuracy of regleadingv sides of their teeth straight, while yltlie back sides may-.be beveled ifv desired. y

To these wheels an intermittent movement 1s imparted to traverse the film' aA predetermined distance and then allow it to remain at rest durlng thetime'necessary for the exposure pand- '.5

printing of the film. f The clamping plate D is y:formed with exposure apertures d, with a space d' between them so that half the pictures are printed under the first lamp B and the other half printed under the second lamp B', the film being traversed forward after each interval of exposure. The spaces d' in the clamping plate D between the exposure apertures are each of such a length and so formed concave or otherwise as to permit or cause a slack length or slight loop in the films, and thereby insure correct registration of the perforations in the films opposite each exposure aperture. To assist the movement of the films they may pass respectivelyover and under the pin d2 fitted in the space d'.

lamps the films A A' can fall slack intoa loop a which will allow them to be drawn forward after each exposure a length equal to the number of pictures printed. A movable shutter F is fitted between the lamp B and the clamping plate D to cut off the light at every printing point or aperture @during theftraverse or shifting forward of the films. Instead of a separate shutter, the

In they gap or space inthe machine'between the two grid E may be made with spaces alternating J' In Fig. 2 similar machine shownr with asingle lamp B and two fiat beds C, C', one

above and one below the lamp B, with a clamping plate D at oneside and D' at the other, and two sets of sprockets G, Gr', to carry the films along two sides of the lamp. The exposure apertures d are formed in the plate D, the space d' being as before described to allow the, films to adjust themselves to compensate for any differences consequentupon shrinkage or expansion in either of them and the -perforations therein to register at each exposure aperture. The clampf ing plates D, D', are similar to thoseinFig.

g1. Half' the pictures are printed atIone side of the lamp Band the .other half printed at the' other. side of the lamp, a loop a.' being formed at the end of the machine andtheV films being 4traversed forward aodistance equal to the number of the pictures printed Y after each interval of exposure. 4The lampv B 'maybe of any of the `various well known y forms of mercury vapor lamps, according to the class of work thenachine is intended tol print. Movable shuttersF,- F', are fitted bel tween the' lamp B and the clampingplates D', yto cut off the light at every printing point or aperture during the traverse or shifting forward of the films. Insteaedof made with 'spaces alternating with blanks and as they are moved from one position to the other perform the double function o'f grid and shutter.

In Fig. 3 the apparatus shown is similarV ture d in the clamping'plate. D2, and the 'consequent registration of the perforations. They exposure apertures d are of a width to expose one picture at a time, so that three pictures will be printed at each exposure. The sprocket wheels Gr2 are rotated from the shaft O through the wheels O by mechanismrsuch as shown in Fig. 18. The loop a2 is equivalent to the length of ten pictures, (although a loop the length of three pictures would be sufficient but is not used, as so short a loop would not give as good results Yas the longer one) and at each shift three pictures are moved forward -at a time after each exposure lnterval thus bringmg into the aper-4 tures three fresh pictures for exposure. In thiscase a high candle power mercury vapor lamp B2 ofthe quartz type is shown. A movable shutter F3 is fitted between the lamp B2 and the clamping plate D2 to cut off the light at every printing point or aperture during the traverse or shifting forward of the films. Instead of a separate shutter the grid E3 may be made with spaces alternating with blanks and as it is moved from one po sition tothe other performs the double function "pf grid and shutter. The sprocket wheels bands-or claws are moved on intermittently the required distance by any well known form of intermittent motion. For high-grade accurate printing, and especially for printing in two or three colors by successive printings needing accurate register, I prefer a long lamp which will have a lower candle power per inch and be comparatively cool, such as the standard Cooper-Hewitt type of lamp, giving a light of 6000 candles in 66 inches length, or about 90 candle power per inch. But for very rapid or rush work, where a high standard of quality is not nec ess-ary, such as News Picture Films, I may use one of the mercury lamps of the quartz type, which are much higher in candle power, very short in length, but have a tremendously high temperature. Examples of these are known as the Laboratory of about 3000 candle power in- 4 inches length, or the Pistolet of about 8000 candle power in 6 inches length. These quartz lamps are difficult and dangerous to use for printing on account of the ultra-violet or X rays given ofi", and their tremendous temperature, which the films will barely stand for the requisite printing time. But as they are useful'for .certain work, such a lamp is shown in Fig.

4 applied to one form of this printing apparatus.

In Figs. 6, 7 and 8 the apparatus is shown constructed to carry or suspend the films A and A in long loops a4 between the exposure apertures d in the clamping plates D4 and only 011e picture space is exposed at each aperture. 4The films A A are carried over a series of flanged rollers or bobbins M provided with sprocket wheels m by which the register of the two films is effected and maintained. The loops a4 may pass in lspiral form around a lower roller M similar to that described with reference to a printing, washing and developing machine in my U. S. Letters Patent N o. 1,173,898 and No. 1,173,899, both dated February 29, 1916. The films may travel Alongitudinally of the lamp B4 as in Fig. 6 and receive a half turn on to the bottom roller, or transversely of the lamp B4 as in Figs. 7 and 8. The rollers M may form the supports upon which the films are tightly clamped -during eachexposure by the clamping plate D4, or the bed plate may be formed as in Fig. 4. lA movable grid Ei'and shutter F4 are interposed between the lamp B* and the rollers M to ldirect the light rays perpendicularly to the films and to shut off the light when the films are being moved forward. The Vlength of the loops a* in the lms should be equal to the sum of the lengths ofthe pictures exposed and printed at one time. Thus with a. Cooper-Hewitt lamp of 66 inches longitis possible to have 44 printing points and therefore 44 simultaneous exposures and 44 pictures on the film `printed at one time. The film may thus be shifted an equivalent length 5after each exposure, that is to say that a ,film length of 44 pictures is printed every half minute or for every exposure.

In Figs. 9, 10 and 11 the apparatus is shown constructed to carry the films A and A backwardand forward in a number of spirals transversely of anumber of lamps B5 four being shown. ,The films are wound around flanged rollers or bobbins M2 and M3 and pass between the fiat bed C5 and the clamping .plate D5 with exposure apertures d, a space ai to allow' for a slackness in the tilmsintervenes between the exposure apertures d. A sprocket wheel or roller G5 engages the perforations in the films at each exposure aperture to register them. Each lamp B5 may extend over 44 printing points or exposure apertures and four lamps will give 176 pictures printed at each exposure of 30 seconds, and allowing about an equal time for moving forward the film about 900 hour. Movable grids E5 and` shutters F5 are placed between vthe films andthe lamps, as hereinbefore described. The lamps are so disposed and the spaces between them so ad- .or 1000 feet of film may be printed in an .justed to one another that no part of the film is exposed to light a secondtime. The ap- ,paratus may be disposed vertically as shown' or horizontally.

In Figs. 12 to 17 the apparatus is shown constructed to pass the films circumferen-A tially around a single lamp' B, the-hlm being passed spirally around the flanged bobbins or rollers M6, adjacent to the lamp, with sprocket wheels G to engage the perforations in the {ilms and bring. the two lms into corilm, thereby providing 4X44=176 printing points. Clampingv plates D? are pivoted and brought to and from the rollers or bobbins 'M6 by levers D7 actuated by aycam D?, see Fig. 13, the bobbins being providedwith registering. sprocket teeth G6. A5 shutter E6 is placed around the lamp -to s ut 'off the light during the traverse of the fi ms. This may be -in the form ofa .blind with apertures e to allow the passage of light, to'which a movement to and fro may begiven-by a ratchet wheel e2 on a roller e3 actuated by levers c and-pawls e5 from a cam E", see Fig. 15. A grid F6 is interposed'between the lamp B"6 and the bobbins M6, to which a longitudinal reciprocating movement is im-v parted by an eccentrlc or cam .F7 and connecting rod f, (see Figs. `16 and 17.) To re- ,tain the ilms in position on the bobbins M6 it is desirable to lead them on with a certain amount of tension, and to effect this-two vsuction boxes H H are placed in the path of the films over which the films are drawn by the sprockets (ri and which will allow of registration of .the .perforations by the sprockets. The films AV and A.are carried y forward in a series ofloops gas.. spirally around the rollers or bobbins M',- see Fig.

12. When the films are passed over rollers'. or bobbins such as M, and aV suitable ten-. sion applied thereto 'to maintain them in intimate Contact when passing over the printing points, the clamping plates D may in some cases be dispensed with.. l.

The mechanism for -effecti gj the shift" or known mechanism. *One disposition of gearing for gearing together the sprocket wheels G' to G6. is shown in Figs. 5 and '18 the intermittent gear connecting with the shaft O.A A The intermittent gear comprises a barrel P driven by a weight W, which descends when .the barrel is released, \(to insure a greater pull at .the starting and lesser at the finish y the barrel P for the weight cord is preferably offsnail shape as used in a clock), a crossed 'worm R attached to the barrel with a re-l taining. catch r which traverses to 'and'fro across the worm, va camplate r to' release fro thereon.

the catch l' and mechanism to rotate the I barrel P in the reverse direction and rewind sha-ft sliding ona key and a member T loose` thereon, The loose member T of the lclutch is gea-red through a shaft t andv gear wheels with the barrel P with .a free wheel or one wayclutch -mechanism which permitsthe barrel P to be rotated in the reverse direc- Ytion to windA upthe cord 'of rthe weight W thereon without rotating the shaft O. .'At the end of each exposure of the film the cam plate 1" releases'the catch 7' allowing the wei'ght W to drop and causing the mechanism to rotate andl through the bevel wheels O rotating the sprocket wheels thus moving other exposure is made. The number of pictures and the length of film moved is gov-rv erned A'by the length of the worm R and the period of thetraverse of the `catch1n to and traveled yfromv right to left vandback again it falls into the notch made for it and arrests further movement and rotation until released again by the next revolution of the cam plate r. The weight W when its cord vis ,unwound from the barrel strikes a lever (not shown) and throws the clutch member T into gear with the clutchmember-T to rotate the barrel P in the reverse direction the desired number of-,pictures before an- As soon as the catch r has to wind up the weight. A similar lever (not shown) is again struck by the weight W and throws the clutch member T o ut of gear '-with the member T when the weight is In several of these arrangements the sprockets for' carrying forward` the films maybe replaced by an endless band with sprocket teeth or' pins projecting from its surface to engage the pergorations' in the ilms.

'By this method of printing every printingl point receivesthe same exposure, and 11'0 picture-section is presented to the light mere "than puce, the film being so spaced and moved that the whole strip is exposed in succession. .Light traps of plush or other material may be placed between the'irollers or spools M toy prevent-the passage of light to theother portions of the films.

to protect by Letters Aatent iszfilms comprising a light of 1. Apparatus :for printingfcillematograph. 1g actinicfand.

What I claim as m invention and desire low heating power, a bed over Which'the `f1lms travel,r means to hold the -lms lin inti- 7 mate contact during each exposure. with*V more than two exposure apertures and aplul rality of spaces one between eachppairof apertures, feeding and registering means to 'lamp at each forward -films in which a with loops between engage the perforations in the films to carry them forward, and amovable shutter'inter- Y posed to cut off' the light during the movement of the film, substantiallyv as described.

`2. Apparatus for printing cinematograph films comprising a light of high actinic and low heating power, a bed over which the films travel; means to hold the films in intimate Contact during each exposure; a movable grid interposed between the light and the exposure aperture to cause the light rays to strike the film perpendicularly and thereby insure a sharp image; feeding andregistering sprockets to engage vthe perforations A 1n the films to carry them forward; and a movable shutter interposed to cut ofi" the light during the movement of the film, substantially as described. A

3. Apparatus for printing cinematograph films wherein a plurality `of exposures, more than two, take place. simultaneously, com- 'Aprlsing means for forming a loop in the films inthe plurality of'spa'ces between each pair of exposure apertures to permit of registration of the perforations in the films, and means to intermittently draw the lms forward after ach exposure a distance equal to the umber of pictures printed, substantially as described.

4. Apparatus for printing cinematograph large number of pictures are printed at a time and in which the films are exposed to the light of a mercury lamp tube at a number of printing points each printing point,

means for bringing a picture hsection of the film to an lexposure aperture adjacent to a movement of the film;

means for arresting the film opposite the exposure aperture for sufcient time to givev the .desired exposure; a grid; means for making such exposure through said grid,the grid being'moved during the entire period of exposure, a shutter for cutting off the light, and means for finally shifting the film, during the period in which the light is cut off by said shutter, forward a distance Y equal to the number of pictures printed, in such a manner that no picture space shall appear more than once at a printing point, substantially as described. 5. Apparatus for printing cinematograph films, comprising a mercury vapor lamp; beds over which the films are passed in series of loops to presenta number of printing points at intervals along the length of the film, means to maintain said films in intimate contact against said beds, said clamping means having aseries of exposure apertures equivalent to the number of printing points, to expose all simultaneously, and a shutter to cut off the light while the film is shifted between exposures; and feeding and registering devices to engage the perforations in the film and feed the film intermittentlyforpward a distance equal to the length of the number of the pictures printed, substantially as described. j

6. Apparatus for printing cinematograph lms, comprising a mercury vapor lamp; beds over which the films are passed in series of loops to present a number of printing points at intervals along thelength of the film; clamping devices to maintain the films 1n intimate contactagainst said beds, w

said clamping means having a series .of exposure apertures equivalent to the number of printing points, to expose all simultaneously; a moving grid which is kept moving between the lamp and films during the entireperiod of exposure; anda shutter to cut off the light while the film is shifted benesses.

JOHN EDWARD THORNTON. Witnesses:

J. OWDEN OBRIEN`y GEO. H. OBRIEN.

Images