US1707498A - Motion-picture machine - Google Patents

Description

April 2, 1929. 1. N. STEIGMAN 1,707,498

mono PICTURE MACHINE Filed Jan. 8, 1924 A 4 W A J i 6 ,5 7 I lllllllllllllll'lll k; W

FIG.2

' INVENTQR I lsme/ A! Shy/770W ATTORNEY Patented Apr. 2 1929.,

UNITE ISRAEL IN". S'IEIGMAN', GE BROOKLYN, NEW YORK.

MQ'IION-PICTURE MACHINE.

Application filed January 8, 192 1.

This invention relates to motion picture apparatus and particularly to that type in which each of a series of projected pictures is maintained upon a screen until the next 5 succeeding picture replaces or is superimposed thereon without intervals of darkness between successive pictures.

In mechanism of this character a revoluble ring or wheel of internally reflecting'reflectors is employed for reflecting the picture as a whole to a constant predetermined position on the screen.

Previous arrangements of the above described type of projecting apparatus however, are not effective to reflect a beam of light along a theoretically correct path ex cept as is shown in my previous application for Letters Patent of the United States filed May 3, 1923, Serial No; 636,809. By arranging the mirrors of said ring angularly with respect to the optical axis of the system as hereinafter described, I am enabled to divert the picture out of the machine and on to a stationary area on the screen, while main- 7 taining said optical axis'perpendicular by intersecting the axis of rotation of said machine.

By providing a single moving part, namely, a rotating shaft, and mounting thereon the ring of mirror as well as means for advancing the film I have provided a simple machine having a minimum number of moving parts and have reduced the amount of wear, and the consequent danger of vibration and inaccuracy of projection to a minimum.

In the accompanying drawing, Fig. 1 is a horizontal section and partial top plan view of my improved machine, certain of the parts being omitted for clearness, and Fig. 2 is a front elevation of my improved machine, the course of the light rays being indicated by light lines having arrow heads thereon.

' In the practical embodiment of my invention I provide a preferably cylindrical disclike member 1 which is suitably mounted for rotation on the 2. On or near t e cylindrical rim 3 of the disc 1, I prefer to secure a series of plane reflectors 4 in any suitable manner as by means of the screws 5. -The reflecting surface of each of the reflectors 4 faces the center of the machine so that rays impinging on said surface are reflected inwardly of said machine, and. substantially toward the referably horizontal shaft Serial No, 684,936.

axis of said machine, Each of said reflectors 4 makes an angle of less than 180 with the adjacent reflectors and is preferably secured at or near the rim 3 in such position that when one of said reflectors is rotated to that position wherein the optical axis 20 of the picture projecting system passes through the center of said reflector the reflecting surface of said reflector then makes an angle of between 83 to 87 degrees or thereabouts with said optical axis. Said position hereinbefore referred to may also be described as that in which the maximum cross sectional area of the projected beam is intercepted by the reflecting surface of said reflector 4. In the construction illustrated, one end of the reflector 4; is secured to the rim 3 in contact therewith, while the other end is in spaced relation thereto, in order to arrange said reflector in the proper angular position above described.

For feeding the film 7 preferably continuously a suitable sprocket 6, having the usual film engaging pins projecting radially therefrom, is mounted for rotation on the shaft 2, 1t bemg understood that the said shaft 2, the

' disc 1, the mirrors a, and the sprocket wheel 6, together with the film thereon all rotate as a unit in the direction of the rotational arrows shown in Fig. 2 without relative motion, backlash, wearor vibration.

A cylinder 8 acts as an idler about which the film 7 is passed before engaging the sprocket wheel 6, for changing the direction of movement of said film. Said film is preferably arranged so that during the movement thereof, it is immediately below the jective being so designed as to focus, the

beam of light at a focal point 21, on a line perpendicularly intersecting the axis of rotation of the shaft 2 and substantially coincident with the axis on center line 20 of the optical system. The objective 14 is'so designed that the point 21 falls not quite midway between the axis of the shaft 2 and the rim 3 for the reasons pointed out in my previous application hereinbefore mentioned.

Arranged as closely as is physically possible to the focal point 21 is the upper edge of the reflector 16, inclined in such a manner as to divert those rays reflected by the operative one of the mirrors 4, out of the machine and on to the screen 17, clean of all obstructions.

The operation of my improved machine is as follows: 1

The shaft being rotated in the direction of the arrows in Fig. 2 the film 7 is thereby fed by means of the sprocket wheel 6 at a suitable rate past the opening 10 of the gate 9, light being passed through said film by means of the reflectors 12 and 13. The light passing through the picture is focused at the focal point 21 of the optical system in the usual manner as by means of the objective 14 and the reflector 15. It will be seen that by reason of the angular disposition of the reflectors 4 that that one of said mirrors which is in operative position, that is, which is in a position to intercept the picture reflected by the mirrors 15, diverts said picture downwardly inthe same vertical plane and toward the reflector 16. Said reflector 16 is sufficiently inclined to reflect the picture in turn out of the machine unobstructed by any of the parts thereof. It will be understood that the picture is projected to a stationary area on the screen, movment of the film being compensated for by the rotating ring of reflectors 4 as fully described in my previous application mentioned and as need not be here repeated.

It will be noted that the film is fed with the upper end of the picture toward the left so that said picture appears right side up on the screen. Furthermore it will be noted that the film 7 moving as it does in the direction of the arrow past the gate 9 is so reflected that the image moves relatively. to the reflectors 4 in a direction opposite to that of said reflector, whereby optical compensation for the movement of said film is effected, in spite of the fact that the entire machine including the film rotates as a unit.

It will be understood that since there is a minimum number of moving parts and since the shaft 2 may be suitably mounted in antifriction bearings, not shown, wherein a minimum amount of wear occurs, the accuracy of projection, clear definition, lack of vibration and lost motion inherent in the original structure is maintained at the original efliciency.

I do not wish to be understood as limiting myself to the specific structure shown, as various changes may be made without departing from the spirit of my invention.

I claim':

1. In a motion picture machine, a shaft, means for continuously advancing a film mounted on said shaft, a reflector carrier mounted on said shaft, means for transmit-I ting a beam of light passing through said film toward said carrier along a continuous line, part of which lies in a radius of the machine and for focussingsaid beam at a focal point between the axis of said shaft and the rim of said carrier including an objective arranged in vertical spaced relation to said radius and a mirror arranged in the path of said beam at said radius for changing the direction of said beam, a. series of inwardly reflecting reflectors parallel to said axis and so mounted on said carrier that when each of said reflectors is successively brought into that position in which a line passin through said focal point and through and perpendicular to the axis of said shaft, passes through the center of said reflector, the reflecting surface of said reflector makes an angle other than a right angle with said line, and means for diverting 'said beam out of the machine.

' 2. In a motion picture machine, a shaft, means for continuously advancing a film mounted on said shaft, a reflector carrier mounted on said shaft, means for focussing a beam of light passed through said film at a focal point between the axis of said shaft and the rim of said carrier, inwardly reflecting reflectors carried by said carrier in such positions that when a line passing through said focal point, through and perpendicular.

to the axis of said shaft passes through the center of any of said reflectors, the reflecting surface of said reflector makes an angle other than a right angle with said line, and is parallel to the axis of said shaft, means for transmitting said beam to said reflector along a line lying partly in a radius of said machine whereby the size of said reflector and the focal length of said focusing means is independent of the size of the film picture, and an angularly disposed reflector for diverting the beam reflected by said first mentioned reflectors out of the machine.

3. In a motion picture machine, means for continuously advancing a film, means for passing a beam of light through a part of said film in spaced relation-t0 said advancing means during the movement of the film, means for focusing said beam at a point sub stantially midway between the axis of rotation of said machine and the periphery thereof, a series of inwardly reflecting reflectors, each'parallel to and revoluble about said axis and disposed at an angle other than a right angle to a line passing through said axis and the center of the reflector, said beam being transmitted partly along said line and partly along a line substantially perpendicular to said first mentioned line, and means disposed near said focal point for diverting said beam out of the machine after reflection thereof by said reflector.

4. In a motion picture machine, a shaft, a series of reflectors revoluble about, in spaced relation and parallel to the axis of said shaft operatively connected to said shaft, arranged at an angle other than av right angle to a line perpendicular to and passing through said axis and through the center of the reflector, and arranged with the adjacent reflecting surfaces thereof at an angle lessthan 180, meansiincluding a source of light and a reflecting surface interposed between said source and the reflectors for projecting light on said reflectors in succession along a continuous line, parts of which are in angular relation whereby the size of each reflector is independent of the size of the projected film picture and means for diverting the light reflected by said reflectors out of the machine.

5 In a motion picture machine, a shaft, a series of revoluble reflectors each. arranged parallel to the axis of said shaft and at an angle other than a right angle to a line passing through the center of the reflector and passing through and perpendicular to said axis, means for focusing a beam of light at a point on one of the lines hereinbefore described substantially midway between said reflectors and said axis and for transmitting said beam for part of its length along a second line substantially at right angles to the first mentioned, line and means for diverting the beam reflected by said reflectors out of the machine.

6. In a motion picture machine, a substantially horizontal shaft, a sprocket wheel on said shaft for continuously advancing a film, a reflector carrier on said shaft, of greater diameter than said sprocket wheel, reflectors parallel to the axis of said shaft on said carrier and arranged, when operative, to reflect beams approximately toward said shaft, means for focusing a beamof light passed through said film on a horizontal line at a point substantially midway between the axis of said shaft and the periphcry of said carrier and for so projecting said beam that the virtual image of the film moves oppositely relatively to said reflectors on the rotation of said shaft and the beam is substantially vertical for part of its length, and means for reflecting the reflected beam out of the machine.

7. In a motion picture machine, selfsynchronized means for compensating for the continuous movement of a film comprising means for continuously advancing a film, a

concentrically arranged series of inwardly reflecting reflectors the size of which are independent of the size of the film picture and which are rotatable at the same angular velocity and in the same direction as said film advancing means, for reflecting an image toward the center of said revoluble means and each of said reflectors being arranged at an angle other than perpendicular to a radius of said machine and arranged parallel to the axis of said machine, an odd number of reflectors for projecting the image of the film on to said reflectors so that said image and said reflectors move in opposite directions and means for lighting a portion of the film which is in spaced relation to said film advancing means.

-8. In a motion picture machine, a series of inwardly reflecting reflectors each arranged. parallel to the axis of rotation of said reflectors, at an angle other than a right angle to a line passing through the center of the reflector and passing through and perpendicular to said axis, and at an angle less than 180 degrees with the adjacent reflectors, and means including a reflecting surface arranged inwardly of said reflectors for projecting a beam of light on to said reflectors in succession with the-axis of said beam in part coincident with said first mentioned line and in part substantially perpendicular to said first mentioned line.

9. In a motion picture machine, means for continuously advancing a film, a series of reflectors arranged with the reflecting planes thereof parallel to the axis of said film advancing means, each of said reflectors being arranged at an angle less than 180 degrees with the adjacent reflectors and at an angle other than a right angle to a line passing through and perpendicular to said axis and through the center of each of said reflectors, means operatively connected with said reflectors for projecting an image of said film on said reflector-s from. a point in spaced relation to said film advancing means in synchronization with the rotation of said reflectors, said projecting means including a reflecting surface interposed between said point and said reflectors and a stationary reflector for reflecting the image reflected by said series of reflectors out of the machine.

ISRAEL N. STEIGMAN.

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