US722382A - Animated-picture apparatus. - Google Patents

Description

PATENTED MAR. 10, 1903.

J. A. PROSS. ANIMATED PICTURE APPARATUS.

APPLICATION FILED JAN. 19. 1903.

NO MODEL.

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UNITED STATES PATENT OFFICE.

JOHN A. PROSS, OF OANASTOTA, NEW YORK, ASSIGNOR TO AMERICAN MUTOSCOPE 82; BIOGRAPH COMPANY, OF NEiV YORK, N. Y., A COB- PORATION OF NEW JERSEY.

ANIMATED-PICTURE APPARATUS.

.EWECIFIGATION forming part of Letters Patent No. 722,382, dated March 10, 1903.

Application filed January 19, 1903. Serial No.139,531. (N0 model.)

T0 all whom it may concern."

Be it known that 1, JOHN A. PRoss, a citizen of the United States, residing at Canastota, county of Madison, State of New York, have invented certain new and useful Improvements in Animated-Picture Apparatus, of which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.

My invention relates to machines for exhibiting animated pictures, and has for its object toimprove the effects produced by such machines.

Heretofore it has been found impossible to avoid the wavering or flickering caused by the rapid succession of the different views of the moving object, although numerous attempts have been made to accomplish the same-as, for example, by the use of a specially constructed shutter which obscures the field during the substitution of one picture for the preceding or by the use of a rotating optical system which keeps each successive view momentarily at rest on the screen, although the picture-bearing band itself be continuously moving. Such expedients have been found satisfactory to a certain extent; but they have all possessed in practice certain disadvantages, and I have therefore been led to devise my present invention, which not only is simple in construction and operation and adapted for use with any form of apparatus, but also greatly reduces the undesirable flicker which has always been present in the projection of pictures showing objects in motion. The invention involves a departure from hitherto accepted theories, under which it has always been thought desirable in order to reduce the flicker to the minimum to make the period of exposure of each picture as long as possible in comparison with the period of obscuration during substitution or change consistent with producing the illusion of motion. I have found, however, that by interposing an opaque shutter to obscure the field during the period of substitution or change and also one or more times during the period of rest or exposure the objectionable flickering is very greatly reduced.

The invention therefore, broadly stated, consists in means for obscuring the picture during the period of change and also one or more times between changes. I have shown it in the accompanying drawings employed with a projecting apparatus in which the picture-bearing strip or film is moved intermittently, so as to hold each picture stationary in the field for a certain proportion of the time, which may be substantially equal to the period of motion by which one picture succeeds another, but is preferably considerably longer.

It should be understood, of course, that the use of my invention is not limited to the apparatusjust mentioned, but may be employed with advantage in connection with any mechanism in which the picture or the image remains stationary for a period of time.

Referring now to the drawings for a better understanding of the invention, Figure 1 shows a simple apparatus arranged to operate in accordance with my invention. Fig. 2 is a rear View of the same with the end of the .case and other parts removed. Figs. 3 and 4 show modified forms of shutters.

By means of feed devices of a suitable kind the picture-bearing band or film l is intermittently moved past the aperture 2, behind which is located a source of light. In front of the film or band is the objective 3. At any convenient positionas, for example, immediately in front of the objective-is a shutter 4 of suitable form. The shutter is preferably of the form shown in Fig. 2, having two blades 5 6, each substantially equal in extent to the open or cut-away spaces between them. The obscuringdeviceorshutterisrotatablymounted in any convenient way and has means to revolve the same once for each picture. It will thus be seen that each picture or phase of motion will be thrown on a screen twice, once immediately after it moves into the field, followed by a short period when the shutter intercepts the light, then again when the shutter moves away before the picture is carried out of the field; or, stated otherwise, the period during which the picture is in the field is broken by a period of obscuration. This operation has the effect of very materially reducing the flicker. It is not necessary, of course, that the openings in the shutter be exactly ninety degrees, as they may be increased or decreased at will; but it is essential to the best results that they be symmetrically arranged; nor is it necessary that theishutter have only two openings, since the same effect may be obtained with one of three blades, as shown in Fig. 3, by rotating it at lower speed, or by a half-and-half shutter, Fig. 4, at higher speed. i

I Under some circumstances it may be desirable to intercept the light two or more times during the period of exposure instead of once, and this may be accomplished, as will readily be understood,.by increasing the speed of rotation of the shutter or without changing the speed by a shutter having a larger number of bladesandopenings. Suchdevices,however, are clearly within the scope of my invention.

One very important result accomplished by my invention is that it makes it possible to exhibit moving pictures at a very much lower rate of speed than has heretofore been necessary for good results Where the ordinary form of mechanism is employed, in which the pictui'e-bearing strip is obscured onl iduring the substitution of the, pictures, the flickering is less objectionableif the frequency of the transposition of the pictures is very greatsay forty or fifty pictures per second; but thisinvolves the use of a large amount of film. If the attempt is made to economize in film by exhibiting only twelve or fifteen pictures per second, the flickering becomes very noticeable and objectionable; but by obscuring the picture one or more times during each period, according to the speed of change, the number of flickers per second is increased two or three fold, and the effect upon the eye is much less disagreeable. This operation is analogous to the case of an incandescent electric lamp, which when operated by current of low frequency has an objectionable pulsation, whereas if operated upon a current of the proper high frequency appears to give a steady uniform light. I have also discovered that while the result aimed atnamely, increased steadiness and freedom from flicker-is accomplished to a degree by the employment of a multiplicity of shutter-blades and an inter ruption of the light several times during each exposure and transposition regardless of the proportion and arrangement of the opaque and transparent portions of the shutter, yet under certain conditions better results are obtained when the openings in a shutter are equal to each other in extent and symmetrically arranged with reference to the axis of rotation in the case of a rotating shutter and with reference to the extent and movement when a reciprocating shutter is employed. All of these forms, however, are within the scope of my invention.

I have-found that the loss of illumination caused by the interposition of the opaque portions of the shutter during the periods of exposure of the picture is more than counterbalanced by the elimination or reduction of the flickering normally present when the alternations of light and shade follow each other more slowly.

The mechanism herein "shown and described represents merely one embodiment of my invention, which obviously may be embodied in apparatus of widely-varying forms, so long as they are arranged to intercept the light one or more times during each period of exposure as well as during the period of substitution or change.

What I claim is g 1. In an apparatus for projecting a series of pictures of successive phases of moving objects, the combination with'means for exposing the pictures in rapid succession, of means for intercepting the light during each period of substitution of the pictures, and also one or more times in each period of exposure, as and for the purposes set forth.

2. In an apparatus for projecting a series of pictures of successive phases of moving objects, the combination with means for exposing the pictures in rapid; succession, of a shutter arranged tointercept the light during the periods of substitution of the pictures, and also one or more times between successive substitutions, as and for the purposes set forth.

3. In an apparatus for projecting a series of pictures of successive phases of moving objects, the combination with means for exposing the pictures in rapid succession, of a rotary shutter arranged to intercept the light during the periods of substitution of the pictures, and also one or more times between successive substitutions, as set forth.

4:. In an apparatus for projecting a series of pictures of successive phases of moving objects, the combination with means for exposing the pictures in rapid succession of a rotary shutter having a plurality of blades and openings symmetrically arranged, adapted to intercept the light during the periods of substitution, and also one or more times between successive substitutions, as set forth.

5. In an apparatus for projecting a series of pictures of successive phases of moving objects, the combination with means for exposing the pictures in rapid succession, of a rotary shutter having a plurality of symmetrically-arranged blades of substantially equal extent, adapted to intercept the light during the periods of substitution of the pictures, and also one or more times between successive substitutions, as set forth.

6. In an apparatus for projecting a series of pictures of successive phases of moving objects, the combination with means for exposing the pictures in rapid succession, of a rotary shutter having a plurality of symmetrically-arranged blades and openings of substantially equal extent, adapted to intercept the light during the periods of substitution of the pictures, and also one or more times between successive substitutions,as set forth.

JOHN A. PROSS.

Witnesses:

HERMAN GAsLER, .I. S. PIOKEL.

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