US1721425A - Glass picture-projecting device for cinematographic apparatus - Google Patents

Description

y 15, 1929- w. WINZENBURG 7 L GLASS PICTURE PROJECTING DEVICE FOR CINEMATOGRAPHIC APPARATUS Filed March 24, 1926 17 Mhzenhuy" Patented July 16, 19 29.

UNITED STATES i 1,721,425. PATENT orrice,

WILHELM WINZENBUBG, OF KRAGENHOF, NEAR (ZASSEL, GERMANY,

GLASS PICTURE-PROJECTING DEVICE FOR CINEMATOGRAPHICAPPARATUS.

Application filed March 24, 1926, Serial No. 97,149, and in Germany March 19, 1923.

' thattbc rays of light have already superposed one another completely when arriving at the picture window. It, however, the reflector lamp is employed for the projection of (ha-pictures, also the shadow becomes visible upon the dia-positive and is, consequently, reproduced on the screen.

The object of my invention is to overcome this drawback, and in designing the means for this purpose I have paid attention to the fact that the existing reflector lamps have proved useful for cinematographic projection and that it is, therefore, not desirable to alter them. Now, I attain the object in view by utilizing a shadowless portion of the ray path, more especially, by directing parallel to the optical axis of the lamp the main ray of such a pencil of said shadowless, portion. This idea of invention can be embodied in several constructional forms, one of which is illustrated diagrammatically and by way of example on the accompany ing drawing. Before entering into the details thereof, I state, that the constructional fol-n1 shown is particularly suited to project. besides cinematographic pictures -by means of the reflector lamp, also stationary dia-glass-pictures with the aid of a stationary lamp in such a manner that no shadow is to be seen. I

Obtaining an unobjectionable dia-projection with a search-light lamp is possible only if a shadowless part-of the ray-path is picked out and then this shadowless pencil paratus being now adjusted for glass picture is used for the dia-projection. The employment of ordinary mirrors for deflection of a pencil for the purpose of (ha-projection is known.

y The figure shows a vertical longitudinal section through a lamp casing, together with 'a side-view of the lamp 'proper and of a mechanism designed for operating an additional reflector and a diaphragm (14-) according to this invention. Y On the drawing, 1 denotes the lamp cas ing, and2 a horizontal adjusting rod'which is guided in a bracket 2' attached to the top of the casing. 3 denotes the additional reflector which is. aflix'ed to a spindle 16 provided with an arm 17 connected by a pin 18 with two links 13 and 13', of which 13 establishes a connection withthe inner end of therod 2, whereas 13' establishes a connection with a bell-crank lever 19- fulcrumed at 15 to a bracket 20 and carrying a circularly curved diaphragm 14.

It is obvious that the reflector 3 and the diaphragm 14 can be moved simultaneously by shifting of rod 2.

5 denotes the arc lamp, and 4 the reflector oi the same. When the rod 2 is moved in the direction indicated by the arrow the auxiliary reflector 3 will be turned out of the path of the rays coming from the main reflector 4, and simultaneously therewith also the diaphragm 14w-ill be turned out of that path, the diaphragm being moved downwards, whereas the auxiliary reflector is moved upwards, as will be clear without a more detailed explanation.

6 denotes a dispersing lense located above the are lamp, and 7 is a third reflector or a mirror which is adjustable and upon which is thrown, by the intermediary of the reflector 3 and the lens 6, a part of the 'rays coming from the reflector 4. The size and shape of the lens 6 is such that the rays impinging upon the reflector 7 are deviated into the projection axis and pass then through a collecting lens 8 to the dia-glass-picture 9. The focal distance of the lens 8 is such that the rays coming from it are being collected in the (ha-objective 10. j

.11 denotes the picture window for the cinematographic projection, and 12 the cinematographic objective. When the movable parts of the mechanism are in the position shown in the drawing, the members 11 and 12 are shut off from the rays, the approjection. I claim:

1. A glass picture projection device for cinematographic apparatus, comprising, in

shadow cast by the carbons of the said lamp, 1

a movable diaphragm located between said lamp and the picture gate in the shadowless portion of the raypath, and means for mov ing said auxiliary reflector and said diaphragm simultaneously, substantially as set forth. 4

2. A glass picture projection device for cinematographic apparatus, comprising, in combination, means for glass picture projection, means for cinematographic projection a reflector arc-lamp, a movable auxiliary re- .flector so arranged as to be adapted to separate from the path of the rays emitted by said lamp a portion thatis free ofthe shadow cast .by the carbons of the said lamp, a movable diaphragm located between said lamp and the picture gate in the shadowless portion of the raypath and a dispersing lens located in the lamp casing and arranged in the. path of the rays coming from the said' auxiliary reflector, substantially as set forth.

3. A glass picture projection device for cinematographic apparatus, comprising, in

. combination, means for glass picture projection, means for cinematographic projection, a reflector arc-lamp, a movable auxiliary refiector so arranged as to be adapted to sep= arate from the path of the rays emitted by said lamp a portion that is free of the shadow cast by the carbons of the said lamp, a movable diaphragm located between said lamp and the picture gate, means for moving said auxiliary reflector and said diaphragm simultaneously, and a dispersing lens located in the lamp casing and arranged in the path of the rays coming from the said auxiliary reflector, substantially as set forth.

In testimony whereof I afiix my signature.

\VILHELM WINZENBURG.

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