US600688A - Photomechanical-plate holder - Google Patents

Description

(No Model.) 4 Sheets-$heet 1.

11. GOODWIN. PHOTOMEGHANIGAL PLATE HOLDER.

.No. 600,688. Patented Mar. 15,1898.

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H. GOODWIN.

' PHOTOMEOHANIOAL PLATE HOLDER. No. 600,688. Patented Mar. 15,1898.

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Patented Mar. 15,1898.

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H. GOODWIN. PHOTOMEGHANIGAL PLATE HOLDER.

ATTDRNEYS,

UNITED STATES PATENT QFFICEQ HANNIBAL GOODWIN, OF NEVARK, NE\V JERSEY.

PHOTOMECHANICAL-PLATE HOLDER.

SPECIFICATION forming part of Letters Patent No. 600,688, dated March 15, 1898.

Application filed uly 20, 1896. Serial No. 599,797. (No model.)

To all whom it may concern:

Be it known that I, HANNIBAL GOODWIN, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Plate and Screen Holding Boxes for Cameras; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to let-. ters and figures of reference marked thereon, which form a part of this specification.

The objects of this invention are to provide an adjustable screen and plate holder for photographic purposes which will more completely accommodate itself to the various conditions and requirements involved in photographic processes.

More specifically, and, first, in regard to the screen-holding portion, the objects of the invention are to provide for very minutely different and definite adjustments of the screen toward and from the sensitive plate; to secure mathematical parallelism between the sensitive plate and the screen; to maintain a parallelism in adjusting the plates within the range of movements thereof; to obtain an easy, convenient, and rapid operation of said parallel parts; to obtain the ready adaptation of screens of all sizes from one inch in dimension up through all ordinary sizes to the largest that can be employed; to secure a micrometrical shifting of the position of the screen from one-thousandths of an inch upward during exposure of the negative without interrupting the exposure in order to secure more perfect gradations of tone and greater contrasts between the high lights and shadows in the final print; to secure a larger and freer shifting of the screen than the micrometrical adjustments above referred to from one-sixteenth of an inch through all intervening distances up to several inches; to enable the screen to be changed by a rotary motion with case, so as to obtain intersecting lines in the negative of all possible inclinations or angles and so securing not only diagonal effects in a negative by the use of a cross-line screen ruled parallel with the sides thereof, but also 'a single screen with only single parallel rulings to be utilized in obtaining cross-line negatives for monochromatic printing-plates as well as obtaining diverse negatives for polychromatic printing-plates; to allow for the ready removal and replacing of screens for cleaning and other purposes without the removal of the screen-holder, and for other required adjustments well known to the process photographer, such as converting the photographic holder into an ordinary copying holder without removing the screen-holder, the said screen-holder being usable in connection with ordinary plateholders, whether they consist of a kit,-a nest of kits, or other devices; but, secondly, and with reference to the preferred plate-holder, the objects are to obtain a plate-holder which prorides for holding the focusing-glass, and thus dispensing with the framed carrier for said glass; for holding the sensitive plate fixedly without the usual spring at the back, and thus allowing thin plates to be used without danger of either breaking or bending and coming in contact with the screen in front; to obtain the minutest micrometrical shifting laterally of the position of the sensitive plate during exposure in order to accentuate the contrasts between lights and shades while copying subjects; to secure the longitudinal shifting of the plate to any desired distances from the minutest to the greatest possible within the limits of the holder; to secure the rotary movement of the plate in order to form from lines in the front screen or in the subject being copied intersecting lines in the negative of all desirable degrees of angularity; to secure, in conjunction with suitablyproportioned masks occupying the place of the front screen or combined therewith upon one and the same sensitive plate, several differently-posed portraits of the same person or several negatives of different subjects, and to provide other adjustments for other purposes desired by process photographers, and to secure other advantages and results, some of which may be referred to hereinafter in connection with the description of the working parts.

In what is known as a half-tone screen the little square openings through which the light is projected are very small, averaging not more than one three-luindredths of an inch square.

It is understood and maintained by the .ablest expounders of the theory and practice of the half-tone process that in order tosecure the best results the screen should be placed at different distances in front of the sensitive plate during the exposure for the negative, nearer to the sensitive plate for securing detail in the shadows of the subject, farther away for obtaining the best hi gh-light effects, and it is further maintained that only by this change of screen distances during the exposure can be best utilized the all-important defraction effects of light.

It is evident that the screen when placed at different distances in front of the sensitive plate must maintain each screen-openin g on the same optical axis throughout the different distances-4. 6., the screen in being moved from the sensitive plate or toward it during the exposure for the negative must move in a line perpendicular to the sensitive plate, for if the screen when thus moved should diverge from the perpendicular a projection of light through an opening of the screen will make its impression at one point of the sensitive plate, and the same projection through the screen standing at another distance will make its impression on another point of the sensitive plate, thus resulting in a double image or a tendency thereto,andtl1erefore it is evident that any mechanical device which in moving the screen to different distances in front of the sensitive plate at the same time moves it laterally and off the perpendicular is most defective. To maintain the screen in this exact aforesaid perpendicular relation throughout its different distances requires very exact mechanical means. The most careful use of thehand could hardly prevent some slight displacement, resulting in a loss of registry of the light projections, and yet it is recognized to be an advantage if after exposure at a certain distance of screen in exact register the screen is moved briefly to either side in a miehrometric distance with the view of giving breadth to the shadows in the final print and likewise with the View of improving the high lights.

The invention consists in the improved dark box for cameras for the use of process photographers and others and in the arrangements and combinations of parts, all substantially as will be hereinafter set forth, and finally embraced in the clauses of the claim.

Referring to the accompanying drawings, in which like letters and figures of reference indicate corresponding parts in each of the several views, Figure 1 is a plan of the dark box, showing the screen-holding devices and sliding lid being removed. Fig. 2 is a section of the same, taken at line at. Fig. 3 is another section taken at line y Fig. at is an edge view showing certain adjusting devices more clearly. Fig. 5 is a plan showing the plateholding devices. Fig. 6 is a plan on a reduced scale showing a construction sometimes preferred with the screen-holding devices up or forward, certain rotating or plate-turning devices being dispensed with. Fig. 7 is a re verse plan-showing the sensitive-plate device. Fig. 8 is an enlarged section taken on line a, Fig. 6. Fig. 9 is a section on line .2"; and Fig. 10 is a section on line .2, Fig. '7. Fig. 11 is a detail plan showing another modification sometimes preferred.

In said drawings, a indicates a box adapted to be arranged and operated in connection with the camera as ordinary plate-holders are arranged and operated. Said box is open at opposite sides and is provided with the usual hinged lid 1) and slide 0, which act to cover or uncover the plates and screen in the manner common to said parts. \Vithin said box a are formed shoulders (Z c for the screen and plate carrier supports, respectively, said shoulders being either integral with said frame or otherwise formed to hold the said supports parallel with one another within the holder. Upon the shoulders e, at opposite sides of the box and nearer the slide 0, are arranged sliding racks 3 3 for holding the screen-carrier-supporting frame f. Said supporting-frame f is given a movement to and from the sensitive plate, while maintaining its parallel relation to the said sensitive plate by means of said sliding racks or the wedges or inclines 4 4., formed or secured thereon. Said frame f is preferably slotted or cut away to receive said wedges at or near the corners thereof. Said racks are moved longitudinally backward and forward on the shoulders e by means of pinions 5 5, arrangedin connection with a shaft 6, having its hearings in the box and having a finger-piece 7 at one end on the outside of the said box, as shown in Fig. 1. By turning the finger or piece 7 and the pinions 5 thereon the racks engaged by the pinions are caused to slide on the shoulders of the box, so that the wedges a, hearing at their inclined sides upon the supporting-frame f, raise the said frame or admit of a lowering thereof to or from the sensitive-plate carrier, as will be understood, and maintain an exact parallelism between the screen-carrier and sensitiveplat-e carrier, while one is being raised or lowered from or to the other, Iemploy at least three inclined or wedge-shaped bearings, two of which are at one side of the carrier and at least one,preferably two, on the opposite side. These opposite wedge orinclined bearings are movable simultaneously and together, the three or more bearings being mechanically connected or in train each with the others and with a common finger device whereby when said finger device is operated all said bearings are uniformly and simultaneously operated to cause uniform elevation or lowering of all sides of the carrier and the sensitive plate or screen carried thereby. Thus the plate and screen, while being separated or brought toward one another, are maintained positively in parallel planes, so that the resulting picture will be uniform in strength, tone, or finish, as will be understood.

As before indicated, I prefer to employ four wedges. These are arranged in pairs, so as to secure a greater firmness or positiveness of action. The individual members of one pair is disposed near the opposite corners of the carrier at or near one side thereof, while the second pair is disposed near the corners of the opposite side. In this preferred construction the wedges are arranged two on each rack.

Springs 8 are employed to lower or press back on the supporting-frame and hold it upon or against the wedges. They may be arranged or disposed in any suitable manner.

At the center of the frame f the same is preferably provided with a large round opening, in which the screen-carrier 7b is nicely fitted so as turn therein impelled by a pinion 9, which meshes with a curved rack 10, which last may extend either partly or entirely around the central opening. In the last case the said carrier may be made to rotate, although ordinarily a partial rotation or turning will be sufficient for the purposes of the invention. The carrier 71. also has a large opening, preferably of a parallelogram or of a rectangular form, as shown, and in the said opening are arranged sliding clamp members 2' i, the opposite ends of each of which have bearings in waysjj, formed at opposite sides of the opening. The clamp members 2' of the screen-carrier are parallel one with the other and are connected by parallel rods 7t 7.; with slides Z, working in suitable ways 171, formed in the body portion of the carrier.

The connectingrods 7e are pivoted to the clamp members and slides and are disposed at inclinations to said parts, as shown, so that by operating the slides longitudinally within their ways, using the set-screws n as fingerpieces in the operation, the said clamping members are thrown to or from one another to clamp or release the screen-plate. The clamping edges of the said clamping members are provided with suitable means to engage the edges of the screens and prevent lateral displacement, such as the flanges o 0 and turnbuttons or spring-clips 17, between which the screen-plates may be inserted. Stays q q serve to hold the carrier in the support in any suitable manner.

To shift the support f, the carrier h, and the parts operated thereby a very limited distance within the box, I have provided a micrometric adj usting-screw r, by turning which I am enabled to force the said support from one to two one-thousandths of an inch, more or less, in one direction or the otherin order to give a variation in the width of the photographically-impressed lines in the negative, depending upon the various amounts of light passing through the transparent lines or dots of the screens and thereby to aid in giving greater contrast to the lights and shadows and fuller color in the middle lights, all even tuating in a more perfectly graduated print. The saidmicrometric adj Listing-screw works in a short slot 0', which allows for the movement of said screw with the support f when operated by the wedges.

To fasten the screen-plates, which may either be very small or of a large size,witl1in the capacity of the box, I simply loosen the setscrews or linger-pieces n and move the slides Z longitudinally, so as to close the clamps 2' against the edges of the said screen-plates, after which the slides are again fixed by the said set-screws and the clamps and screen held firmly in place. Then by turning the finger-piece 90, in connection with the pinion 9, the screen is turned so that the lines of said screen will lie at any desired angle or be varied from time to time, as circumstances may require.

By turning the finger-piece 7 and its shaft 6 and pinion 5 and thus operating the racks and its wedges or inclines 4 the screen is moved to and from the sensitive plate in order to vary the diffusion of light acting on the sensitive plate, and as a consequence I am enabled while maintaining parallelism between the screen and the sensitive plate to locate the screen so precisely that the light from the lens-aperture after passing through the apertures of the screen will converge with the greatest concentration on the smallest possible point of the sensitive plate, such pointed concentration being needed to secure the requisite sharpness and intensity of the small dots in the shadows of the negative, and then, secondly, I am enabled to so further alter the position of the screen as to secure upon the sensitive plate a greater diffusion of the light which passes through the apertures of the screen, by which diffusion the high lights can be sufficiently exposed during the needed exposure without materially enlarging the dots already formed in the shadows, and these results are secured while employing a single lens-aperture throughout the exposure; or after having, as before described, put the screen into that position favorable for securing the beforesaid kind of detail in the shadows I can then insert into the lens a larger diaphragm and thus effect a final closing of the high lights.

In determining which of the two forms of screen-holder in practice is to be employed, whether the circular or the rectangular, I am guided by the following considerations: I em ploy the rectangular form when the screen is of a checker-board pattern, or when the screen is of the ordinary cross-line pattern ruled diagonally to the sides of the screen, or when a larger screen than can be gotten into the circular form of screen-holder is required, and when negatives for only ordinarily halftone work are needed; but as screens of the chessboard pattern, as well as those of cross line pattern which are ruled diagonally, are necessarily expensive, I therefore employ the circular form of holder, as by this I am enabled to get in the negative diagonal rulings from the use of those cross-line screens that are ruled parallel with the sides of the screen,

these latter patterns being cheaper because manufactured at a less expense. I also employ the circular screen-holder in order to utilize screens consisting of not only single lines ruled straight or waving, but of wider and fewer lines than are practicable in other patterns, not only because screens thus ruled are much cheaper on account of their easier construction, but because these single-line screens, after they under a given exposure have produced one set of lines on the negative, can be turned by the device exterior to the box to another point and there, under a given exposure, produce on the negative another and intersecting set of lines, intersecting the first set at an angle, say, of ninety degrees, and then to secure new results in the final print they can be turned by the same exterior device to another point and there, under a given exposure, produce another and intersecting set of lines intersecting the last set of lines at an angle of, say, forty-five degrees, and then, finally, they can be turned to still another point and there produce still another set of intersecting lines intersecting the last-made set at an angle this time of ninety degrees.

\Vhile the first two sets of lines may be normally accentuated and enlarged by the prolonged action of light from the lens in com bination with both the to-and-fro movement of the screen and the micrometric lateral shifting thereof, the last two sets of intersecting lines may be produced narrow and sharp on the negative by means of drawing the screen as close as possible to the sensitive plate during exposure and by not shiftin g them laterally by the micrometric device.

By means of the first two sets of intersecting lines thus operated, and still more when in conjunction with the last two sets operated as described, negatives can be secured which will yield final prints less screeny in appearance with much increased gradation of tone and with lights and shadows rendered in theirproper value.

It is to be noticed that the foregoing results are obtained simultaneously with the exposure of the sensitive plate .and by means of devices operated outside of the box, and it is further noticed that by this circulating screenholder,in conjunction with the to-and-fro motion of the screen and the micrometric shifting thereof, successive negatives can be secured admirably adapted for what is called and well known as the three-color process.

The photographically-sensitive-plate-supporting devices are,lil e the screen-supporting devices, adjustable, so as to raise or lower the said plate to or from the screen or to move it laterally, micrometrically, or pi votally or to clamp it in any desired position within the scope of the clamps, and with these ends in view I arrange upon the shoulders d, within the box a or upon racks (not shown) corresponding in construction with the racks 3, a supporting-frame 13, having a large round opening to receive a corresponding sensitiveplate carrier let, having ways 15 15 for parallel clamp members 10 16 and ways 17 17 for slides 18 18, which lie parallel with said clamp members and are connected thereto by inclined and parallel connecting-bars 2O 20. The said sensitive-plate carrier is also in the preferred construction provided with a curved or more or less completely annular rack 19, which is engaged by a pinion 21, operated from outside of the box by a finger-piece 22 and shaft 23. A micrometric shifting or adjusting screw 2&1 also serves to throw the sensitive plate directly to one side or the other an extremelylimited distance.

I may dispense under certain conditions with the rotary or turning devices, as shown in Figs. (3, 7, S, 9, and 10, also with the raising and lowering rack devices, in which case the carrier may bear directly upon its shoulder, or while preserving the rotary devices I may dispense with the wedges or inclines, and in this case, too, the carrier may bear directly upon its shoulder. I may also, where I desire to secure a greater range of movement of the clamps, multiply the clamp members, as in Fig. 11, where the clamp members 16 are supplemented by parallel clamp members 24-, connected by inclined rods 25 to slides 20 upon said clamp members 16.

Vith reference to the mierometric motions of the sensitive-plate holders, I may add, I am not only enabled to get effects substitutional for or supplementary to those produced by the micrometric movement of the screen, but in the ordinary copying of a subject in the absence of a screen in front of the sensitive plate I am enabled by the micrometric movement of the holder during short periods of exposure to favor or disproportionately accentuate the lights of the picture over the shadows and thus benefit the final print by turning out a picture having contrasts and force which otherwise would be only flat.

IVith reference to the rotary or turning feature of the device I may add to what has already been said in the statement of the objects of the invention that perhaps the most prominent object is to enable me to employ a single sensitive plate in securing several negatives of the same or different subjects by means of shutting off or masking the light from all parts of the plate, except where the immediate negative is being impressed, and then after a change in the pose of the person or the substitution of a new subject turning the plate-holder to a second position, so as to get another adjoining negative, and continuing the operation until the plate is filled.

Other variations in the details of construc tion may be employed without departing from the scope or spirit of the invention.

Having thus described the invention, what I claim as new isl. The combination with the slide or box having lids or covers, of a screen-carrier and a photographically-sensitive-plate carrier, ar-

ranged in said box in parallel planes, and one being movable bodily from the other in lines perpendicular to the planes of each, and carrier-moving means arranged at opposite sides of one of said carriers, a plurality of such means being arranged at one side and at least one on the opposite side for moving the one carrier from the other, each of said means being movable simultaneously with the others and imparting a uniform or equal degree of motion to the said movable carrier, whereby one of said carriers is raised from the other said carrier without departing from a parallel relation therewith, means for connecting the plurality of moving means at one side of the carrier and means for simultaneously and uniformly operating the moving means on opposite sides of said carrier, substantially as set forth.

2. The combination with the slide or box having lids or covers, of a screen-carrier and a photographically-sensitiveplate carrier arranged in said box in parallel planes, one carrier being movable bodily from the other, racks arranged at opposite sides of one of said carriers, one of which racks is provided with a plurality of wedges or inclines and the other with at least one of such inclines, a shaft extending from one rack to the other and having pinions meshing with said racks and effecting a simultaneous operation of the two racks, substantially as set forth.

3. The combination with the slide or box of a camera, having lids, of a screen-carrier, a photographically-sensitive-plate carrier arranged in said box, means for moving one of the said carriers bodily from the other in a direction at right angles to the plane of the carrier, the moving means bearing on said carrier at three or more points one bearing being disposed at the opposite side of the car rier from that engaged by the remaining two, connecting means for operating the three bearings, uniformly and simultaneously, and a micrometer adjustably attached to one of the carriers and bearing on the slide or box and movable with said carrier to and from the second carrier, whereby the said carrier and its contents may be adjusted micrometrically in its plane, in any of the planes at which it is set by the moving means first referred to, substantially as set forth.

4. The combination with the slide or box having a transverse slot and lids or covers, of a screen-carrier, a photographically-sensitiveplate carrier arranged in said box, and a micrometrical adj usting-screw arranged in the slot of said box and attached to one of said carriers and movable at right angles to the plane of the carrier to which it is attached with said carrier and adapted to move said carrier horizontally or laterally or in its own plane when stationed in any of the planes within the limit of its perpendicular movements, substantially as set forth.

5. The combination with the slide or box having lids or covers, of a centrally-open carrier having therein clamp members parallel with one another to engage the opposite sides of the rectangular plate or screen, parallel rods inclined to said clamp members and 0011- necting the same with said carrier, and slides arranged on said carrier and connecting said inclined and parallel rods, and means for setting or fixing said slides, substantially as set forth.

6. The combination with the slide or box having lids or covers, of a carrier, a frame f, having a round central opening, a second carrier arranged to rotate or turn in said round opening, means for turning said second carrier in said opening, said carrier having a rectangular opening, within which parallel clamps are arranged, parallel inclined rods connecting said clamps to the opposite sides of the said second carrier, means for operating said inclined rods and for fixing the same to said second carrier, means for moving said second carrier in a direction perpendicular to its plane and maintaining a parallel relation with the first carrier during said perpendicular movement, the said second carrier being thus adapted to be turned in various planes distant from the plane of the first carrier, substantially as set forth.

7. The combination with the slide or box having lids or covers, of a carrier, a framef, having a round central opening, a second carrier arranged to turn in said round opening and having an opening and clamping devices, means for moving said carrier in a direction perpendicular to its plane and maintaining a parallel relation during the whole perpendicular movement, the said second carrier bein g thus adapted during exposure to be turned in different planes at various distances from the first carrier, substantially as set forth.

8. The combination with the slide or box having lids or covers, of a screen-carrier and a photographically-sensitive-plate carrier arranged in said box in parallel planes one of said carriers being movable one from the other in lines perpendicular to the plane of the other and carriei moving wedges engaging one of the carriers, a plurality of such wedges engaging one side of the carrier, near the opposite ends thereof, and at least one wedge engaging the opposite side of said carrier, each of said wedges being connected to common motive devices and imparting a uniform degree of motion with the others to the carrier, whereby said carrier is moved perpendicular without departure from its parallel relation to the other carrier, and springs hold in g the carrier positively to the wedges, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 25th day of June, 1896.

HANNIBAL GOODWIN.

Witnesses:

CHARLES H. PELL, O. B. PITNEY.

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