US2480178A - Light conductor - Google Patents

Description

I. H. ZINBERG LIGHT CONDUCTOR Aug. 30, 1949.

2 Sheets-Sheet 1 Filed May 8, 1946 INVENTOR. IYAN H. ZINBERG Iv H Haifa? BY MW y W Aug. 30, 1949. l. H. ZINBERG 2,480,178

LIGHT CONDUCTOR Filed May 8, 1946 2 Sheets-Sheet 2 Patented Aug. 30, 1949 UNITED STATES PATENT OFFICE LIGHT CONDUCTOR Ivan H. Zinberg, Newark, N. 1.

Application May 8, 1946, Serial No. 688,055 8 Claims. (Cl. 240-1) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to lighting devices for illuminating a television studio, a stage or motion picture set, a photographic shop, a store window or display or any similar location, and the individuals connected with same without subjecting such to the efiects of heat when intense lighting is used.

At the present time a serious problem confronts television and motion picture studio operators because the stage set to be televised or photographed in motion or in still pictures must be intensely illuminated both with spot or high lights and with soft or difiused lights. This system has the disadvantages in that such a great quantity of light causes a great and uncomfortable amount of heat so that it can only be borne for a limited time by theactors or other persons being televised or photographed.

Accordingly, it is an object of this invention to provide a new and improved lighting device that will avoid one or more of the disadvantages and limitations of the prior art.

It is a further object of this invention to provide a lighting device which makes it possible to supply adequate illumination, either intense or difiused, to a selected location without at the same time causing excessive and disagreeable heating.

More specifically, it is an object of this invention to provide a lighting device employing an electric light bulb which furnishes a point source of intense light which is, however, concentrated mainly in the visible spectrum and contains but a minimum of the longer infra-red or heat rays.

It is yet another object of this invention to reduce the number of light sources required to adequately illuminate any of the locations suggested above by being able to use a small number of relatively high-intensity point sources of light.

An additional object of this invention is to improve the acoustic properties of the location at which the lighting device of this invention is placed because of the broken or serrated surface of the light source employed.

Other objects of this invention will be readily apparent to those skilled in the art to which it appertains or will become obvious from a consideration of the annexed drawings and accompanying specification to which reference is here made for a further and more complete disclosure oi. the present invention.

In the accompanying drawings, forming a part 2 hereof and in which like reference characters are applied to like parts throughout,

Figure 1 is a view in side elevation with parts broken away showing the lighting device of this invention,

Figure 2 is a diagrammatic perspective view with the casing and slide shown dotted,

Figure 3 is an exploded view in isometric projection on an enlarged scale with parts broken away more clearly to disclose the light source, an

Figure 4 is a diagrammatic view showing a pinrality of lens structures and lines for rotating them.

One embodiment of this invention which has been selected, from among many others which the invention may take, for illustration in the drawings and description'in the specification, is as follows.

The lighting device of this invention comprises a stand or support 35 having slots 36 provided therein for receiving trunnions 3i or other bearings on which is rotatably mounted a parabolic reflector 31 which can be readily rotated about its pivotal support, by means of handle 38. At its front edge, reflector 31 carries a rod or bracket 39 on which the light source In is mounted.

Figure 3 shows the light source Ill in greater detail. It will be seen that it consists of a socket 40 which supports base H of a suitable insulating material from one side of which project prongs l2 forming the means by which current is led to the electrodes which are enclosed within an envelope l3 of suitable transparent material such as glass. The negative electrode or cathode I4 is shown as being in the form of a cylinder having a hollow or depression at its outer end which is packed with a. small layer or globule [5 of a suitable substance, conveniently zirconium oxide. The positive electrode or anode i6 is shown as being in the form of flat disc supported on the base H by means of rods l1 and having in its center, confronting the ends of cathode H, a perforation or opening l8 of but slightly greater diameter of the end of the cathode M. The cathode and anode may be made of tungsten, molybdenum, tantalum, or other high-melting point metal. The envelope is evacuated and then filled with an inert gas, usually argon, to almost atmospheric pressure. The lamp I 0 is customarily operated as a direct current are lamp. It is generally energized by a rectifier or a direct current generator or battery. Suflicient ballast resistance is used in series with the lamp to limit the current of the lamp to its normal value. How- 3 ever, the lamp It may be made with multipl anodes ii which permit the lamp to be operated by alternating current, in which case the lamp acts as its own rectifier. In operation, the arc activity is concentrated upon a very small portion of the cathode so as to produce a very high intensity light source in the form of a luminous circular spot which is fixed in position and sharply defined and uniformly brilliant. This source of light is the incandescent glouble or spot l which forms on the end of the cathode H. The giobule IS on the cathode I4 is but a'few hundredths of an inch from and directly behind the hole It in the center of the anode i5. Hole I3 is slightly larger in diameter than the end of the cathode and provides a window for the emergence of light from the cathode. Lamp ill emits radiation from two main sources, the white hot zirconium cathode globule i5 and a cloud of excited zirconium vapor and argon gas in the cathode glow region which extends for a few thousandths of an inch from the cathode. The globule i5, which is the source of radiation, is a circular spot which is firmly fixed in position, sharply defined and uniformly brilliant. It is very bright, being several times brighter than tungsten filament lamp and almost as bright as the crater of the carbon arc. The globule l5 may be as small as three thousandths of an inch or as large as several tenths of an inch. The lamp will start almost instantly and burn quietly without need of attention or adjustment. It can be burned in any position, is reasonably rugged, and has a life which is measured in hundreds of hours.

Figure 2 shows that lamp In is mounted at or adjacent the principal focus of the reflector 31 which is substantially parabolic at its inner surface. Consequently the rays from the lamp III which fall upon and are redirected by the reflector 31 emerge from the reflector substantially parallel to one another.

The light from lamp l8 and reflector 37 is applied to the desired location such as a television, motion picture or stage set by means of the lens structure I. This lens structure consists of a pile or stack of juxtaposed lens-like portions which, except for their varying lengths, are substantial duplicates. Each of these lens portions has a flat polished inlet end confronting and nearest to lamp II and reflector 31. This inlet end 20 is substantially perpendicular, in normal position, to the rays of light from lamp Ill and reflector 31 so that these rays of light enter the lens portion and are piped or transmitted along it. The main body part 2! of each of the lens portions is substantially rectangular and boxlike in shape. At the far end from the inlet surface each lens portion terminates in a prismlike part formed of a flat reflecting wall 23, which is at such an angle to the plane of the inlet wall 20 as to reflect the beams of light passing or being piped longitudinall of the prism portion and falling onto the reflecting surface 23. Ben'eath the reflecting wall 23 and in that surface of the prism portion which is substantially perperpendicular to the inlet face 20, there is formed an exit surface 24 in' the shape of a hollow trough-like concavity extending transversely of the prism portion beneath the reflecting wall 23. A number of these lens portions, each of different length, are stacked or piled one upon the other to form the lens structure N. If desired, the lens portions can be united into a single homogeneous continuous whole.

The step-like reflecting surface of the lens structure is acoustically desirable for a theatrical stage or set because such a broken or serrated surface does not provide a flat bathe or sounding board for the reflection of sounds. By the use of the stair-shaped or step-shaped lens structure of this invention the necessity of providing specially treated or sound-proofed surfaces is avoided.

A suitable material for makingthe lens structure I9 is an acrylic resin and partciularly a methacrylate. This material is an artificial thermoplastic of crystal clarity and special transparency. It is able to pipe light around curves whose radius is not less than twice the thickness of the sheet of plastic through which th light is being transmitted or around corners which are not greater than 48. Theoretically such material, because of its freedom from internal haze could pipe light for many feet, in fact, an indefinite length. There are, however, certain practical limitations.

1. Such possibility assumes an optically perfect surface which is not practical to produce in quantity when fabricatin or molding such material. The polarity of the light source here employed and the short distance which the lens structure is spaced from the light source render the loss of light energy at the entrance surface to the lens sthucture negligible.

2. It assumes that the surface be free from dust anddirt which might reduce the ability of the material to reflect light. This is avoided by stacking or piling the lens portions with their horizontal faces in contact so that dust and dirt cannot gather on them.

3. There is a limitation on the amount of light which can be reflected into the inlet edge of the material. The high-intensity small-area source of light here employed makes possible the avoidance of this limitation.

The lens structure is may be mounted in a bearing, such as a disc 22, which, in turn, is received in a suitable bearing or support in a hole in the wall 26.

Figure 4 shows that lines 21 are connected to the bearing 22 or other convenient parts of the lens structure, and can be located conveniently adjacent the support or standard 35.

The support or standard 35 has in its sides, slots 36 through which the trunnions 3| project and in which the trunnions 3| are slidable so that the lamp in and the reflector 31 are adjustable vertically and can be secured in adjusted position by means of the clamp screws 32. Because of the bearing of the disc 22 in its supporting bearingfthe end of the lens structure I! and the wall 26 form a continuous barrier which precludes heat from the lamp Hi from entering by conduction or convection the room or stage setting above which thelens structure 19 is located.

Also, it will be seen that the direction in which the light is emitted from the exit portion 24 of the lens structure I! can be varied in three ways.

1. By oscillating the lens structure I9 about its longitudinal axis perpendicular to the wall 26. This is done by pulling the lines 21 and I in the appropriate direction.

2. By tilting the reflector 31 about its pivots 3| by means of handle 38. This varies the direction in which the rays of light fall upon the inlet ends 20 of the lens portions and thus varies the-direction in which the light piped along the lens portions strikes the reflecting walls 23 and consequently the direction in which. the light leaves the lens structure through the exit parts 3. By adjusting thelamp l and reflector 31 vertically of the inlet ends 20. This has the effect of cutting 06 light from one or more of the inlet ends of the lens portions and consequently prevents the light from being piped along the lens portions thus cut ofl.

A slide 33 may be mounted for reciprocating movement horizontally in stand or support 35 so as to cover and uncover the opening formed at the front of reflector 31. or more circular portions 34 each covered with a screen 42 of a difierent color so as to vary the color of the light which passes from the lamp l0 and reflector 31 to the lens structure I9. In addition screen 33 can be arranged so that its intermediate edge or its entire intermeditate opaque portion 5| overlies the opening between lamp l0 and the inlet end of the lens structure so as to cut off all or a part of the light falling on the inlet ends 20 of the lens structure. eliminates light from one or more of the exit portions 24 and gives a concentrated or spotlight effect.

Figure 4 shows that, if desired, a plurality of lamps ill with corresponding reflectors 31 may be mounted in horizontal alignment along the side of a stage or set. Each lamp has above the stage or set a corresponding lens structure IS, the lens structure l9 covering a wall or surface of the stage This Slide 33 may have one 1 composed of a plurality of rectangular box-shaped portions each having a reflecting surface at an angle to said polished surface and confronting said polished surface at a considerable distance therefrom and having a plurality of curved walled channels adjacent to and under said reflecting surfaces and providing an exit for light from said lens structure.

3. A light distributing device intended for the illumination of a selected area, said device comprising, an electric light bulb of the heating cathode type permitting ahigh percentage of visible rays and a low percentage of heat rays, a reflector mounted adjacent said light and arranged to reflect therays which fall onto reflector so that they leave the reflector in substantially parallel rays, and a lens structure of a transparent hightransmitting-efficiency material having a flat light receptive surface on which the rays from said light and said reflector fall and enter the lens structure, said lens structure having its face confronting said polished surface in the form of a plurality of step reflecting surfaces arranged at an angle to or set in the manner of a plurality of side by side cylinders or the slats of a Venetian blind. In such case, the lines 21 and II may be connected to each of the lens structures I9 so that all of the lens structures are oscillated at the same time or any thereon without departing from the principles and spirit of the invention, as sought to be defined in the following claims.

I claim:

1. A lighting device for flooding a selected location with high-intensity low-heat content illumination, said device including, an electric lamp having in its output a high percentage of visible light rays and a low percentage of heat rays, a plurality of lens structures of transparent material, said lens structures having light receiving ends and interrupted light emitting side portions through which light passes out of said lens structures, a mounting in which said lens structures are supported so that they are free to oscillate over a limited arc, an operating member which is connected to one of said lens structures so as to Oscillate said lens structure, and lines connected to said operating member and to the remainder of said lens structures whereby said lens structures can be oscillated to any desired position from a remote location.

2. Means for selectively illuminating an object, comprising, an electric lamp bulb providing a source of radiant light whose radiation is principally in the visible spectrum, a reflector mounted adjacent said bulb so as to receive and reflect rays of light from said bulb, and a lens structure having a flat polished face confronting said bulb and said reflector so that the light from said reflector and from said bulb enters the lens structure through said face, said lens structure being said lens structure from said polished surface, and depressions in said step surface adjacent to and under said reflecting surfaces so as to receive light reflected by said reflecting surfaces and to emit it from the lens structure onto the area to be illuminated.

4. A lighting appliance adapted to vary the intensity and direction of light, said appliance comprising, an electric light bulb having an anode and a cathode arranged to provide an incandescent globule forming the light source, a lens structure mounted adjacent said lamp and having a flat surface through which the light enters the lens structure and a plurality of elongated paths extending substantially perpendicular to said polished surface and each terminating in a substantially flat reflecting surface formed at an angle to said flat reflecting surfaces so as to receive and transmit out of the lens structure the light reflected by said flat surfaces, and a bearing in which said lens structure is movably mounted for rotation upon its longitudinal axis so that the direction at which beam of light is emitted from said lens structure can be varied.

5. An illuminating device for furnishing to selected locations intense radiant light having low heat value, said device comprising, a source of rays which are mainly in the visible spectrum, a reflector for concentrating and reflecting said rays in parallelism, a lens structure composed of a highly transparent artifical material having a fiat wall confronting said bulb and said reflector and providing on its surface opposite said flat face with a plurality of said step-like reflecting surfaces each arranged at an angle to said flat surface and each arranged at a definite distance from said flat surface and each arranged at a definite distance from said flat surface, and a plurality of interrupted portions on the surface of said lens structure and opposite step-like portions so as to receive light reflecting from said step-like portions and to emit it from said body onto the area to be illuminated, and a movable mounting for said lamp and said reflector so that the angle at which the rays of said lamp and said reflector fall onto the polished surface of said body can be varied to and thereby vary the angle of rays of light which are emitted from said body.

6. A mechanism for supplying and directing light onto a selected area, comprising, an evacuated envelope having electrodes in it which furnish a luminous source of visible light, a substantially parabolic reflector mounted so that said electrodes occupy the principal focus of said reflector whereby the rays from said electrodes posed at an angle to the inlet face so as to form reflectors which reflect light passing from the inlet face through the lens structure to the riserlike portions and out of the lens structure through the tread-like portions, and a bearing for said lens structure providing a movable mounting in which said lens structure can be rotated about an axis substantially perpendicular to its inlet face.

7. A lighting device for illuminating a predetermined area, including, a source of radiant energy comprised chiefly of visible rays but including a minor proportion of heat rays, and an elongated body of a highly transparent material which transmits light rays and prevents the transmission of heat by conduction or convection, said body having smooth light-transmitting end mounted opposite said source so as to receive and transmit rays of light from said source longitudinally of said body and having its opposite ends formed in the shape of a series of horizontally off-set wedges each having a sloping face confronting said inlet end and forming a reflecting surface and each having a portion of the face substantially at right angles in said inlet end treated to facilitate the emission of light from supported for oscillation about its longitudinal axis. I

8. A prismatic area-illuminating appliance of the end-light type, including, a body formed of a plurality of juxtaposed rectangular portions each having a flat end wall forming an inlet surface for light and each terminating at its opposite end in a prism-shape surface forming a reflector for the light passing through said portion from the inlet surface and each having a curved trough-shaped depression in a wall at an angle to the inlet wall and confronting one of said refiectors and forming an outlet for light from said body, and means for illuminating the inlet wall of said body with an intense quantity of light.

' IVAN H. ZINBERG.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,102,138 Churchill June 30, 1914 1,740,747 Price 1 Dec. 24, 1929' 1,820,899 Greenewalt Aug. 25, 1931 2,040,264 Mancini et al. May 12, 1936 2,286,014 Rowe June 9, 1942 2,349,012 Spaeth May 16, 1944 2,367,579 Henry Jan. 16, 1945 FOREIGN PATENTS Number Country Date 315,817 Great Britain July 19, 1929 418,975 Germany May 10, 1926 France May 24, 1937

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