US3225243A

US3225243A - Color lamp with spectral filter around filament

Info

Publication number: US3225243A
Application number: US233585A
Authority: US
Inventors: William C Dauser
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-10-29
Filing date: 1962-10-29
Publication date: 1965-12-21
Anticipated expiration: 1982-12-21

Description

Dec. 21, 1965 w. c. DAusER COLOR LAMP WITH SPECTRAL FILTER AROUND FILAMENT Filed OCT.. 29, 1962 2 Sheets-Sheet 1 Dec. 21, 1965 w. c. DAusER 3,225,243

COLOR LAMP WITH SPECTRAL FILTER AROUND FILAMENT Filed oet. 29, 1962 2 sheets-sheet z WQ@ M United States Patent 3,225,243 COLR LAMP WlTI-l SPECTRAL FILTER ARUUND FILAMENT William C. Danser, 458 Melody Lane, North Muskegon, Mich. Filed 0st. 29, 1962, Ser. No. 233,585 16 Claims. (Cl. S13-112) This invention relates to a lamp, and more particularly to a lamp having a controllable, variable color output with an infinite color range, and relates to a monocolor lamp cartridge.

According to present ligh-ting technology, light of a selected color from a lamp is obtained by applying a suitable color filtering material to the bulb surface or by arranging suitable filtering or spectral selector plates adjacent the bulb in the path of the ligh-t. These methods, while often satisfactory, have definite limitations, including (l) the inability to faithfully produce and reproduce true colors, (2) the very limited number of colors which can be projected, (3) the almost complete lack of controllable color variation, (4) the bulkiness, complexity, and multiplicity of elements necessary for even a few different colors, and the great difficulty of projecting a composite light formed of a plurality of combined primary colors on a single axis.

It is therefore an object of this invention to provide a lamp that is capable in and of itself of projecting light of any color in an infinitely variable manner over the entire visible light range.

It is another object of this invention to provide a lamp that is variably controllable to project any selected color, and by a simple dial adjustment, to change color to any other selected color within an infinite variation of visible light, and all from the same bulb. Its output of color shades over the visible range can be altered within a second. Yet, its exterior appears no different from a normal light bulb. It is small and compact. It can be readily plugged into or removed from a socket. No special skill is required to insert it, or to operate it. It provides true color shades. It can combine light to form a composite of colors such as three primary colors, and moreover projects the composite color on an axis as needed, for example, for photographic or related purposes.

It is another object of this invention to provide a lamp capable of infinite color variation, where the colors may be accurately reproduced at any time. Therefore, the compact lamp is capable of repeatedly projecting the same color at any time, and consequently, is valuable in scientitic, theatrical, display, decorative and other elds.

lt is another object of this invention to provide a monocolor lamp cartridge that is small, simple in structure, and capable of projecting a preselected color of any intensity desired. The cartridge is relatively inexpensive and yet extremely useful. It fills a technological gap by providing true color projection of any preselected color within the visible range from a very small unit. lt can be coupled with similar controlled cartridges of different colors to produce primary colors in any proportion and thus enable variable production of any known color, up to and including white.

It is another object of this invention to provide a small monocolor cartridge Ithat can be enclosed in a small translucent envelope and used, for example, as a christmas tree bulb, a decorative display bulb or in a dozen other uses.

These and other related objects of this invention Will be apparent upon studying the following specification in conjunction with the drawings in which:

FIG. l is a side elevational sectional view of the novel cartridge;

FIG. 2 is a side elevational view of a lamp partially broken away to show a plurality of cartridges therein;

FIG. 3 is an enlarged sectional view taken on plane III- III of FIG. 2;

FIG. 4 is a schematic diagram of a typical electrical circuit controlling the lamp in FIGS. 2 and 3;

FIG. 5 is an elevational view of a single cartridge bulb partially broken away; and

FIG. 6 is an elevational View of a modified single cartridge bulb partially broken away.

Basically, the inventive cartridge to be enveloped in a lamp, either in groups or singularly, comprises a source of light in the form of a filament, a multilm spectral selector mantle surrounding and uniformly spaced from the source, and light ray restricting means limiting the angle of incidence of light from the source onto the mantle to provide a selected spectral color output. More specifically, the cartridge includes an elongated, ceramic support and restricting element, the outer surface portions of which lie in an imaginary cylinder, and having a relatively narrow and deep helical groove along its length, a helical light source filament along the bottom of the groove and adapted to project light in a narrow projection angle range out between the walls of the groove, and a multifilm spectral selector mantle around `the outside of the element to transmit only selected light wave lengths for the color desired. The elongated ceramic element may be specifically defined as the surface generated about an axis by a V lying in a plane including the axis and revolving about the axis while moving longitudinally along the axis. The multifilm spectral selector mantle is preferably a coating on a cylindrical, translucent, and usually transparent tubing support such as glass or quartz. Three cartridges preferably `produce primary colors in the envelopes in varying intensities to provide a composite light output of any selected color from the envelope.

Referring now specifically to the drawings, the novel cartridge itl essentially comprises a source of light, usually a tungsten filament 12 adapted to be connected to electrical leads to emit ordinary white light composed of all colors of the spectrum. The helical filament is wound on a filament support and light ray restrictor 14. A multifilm spectral selector mantle i6, usually in the form of a coating on a cylindrical tube 18 of pyrex glass or quartz surrounds the filament and support. Elongated support i4 has an axis extending through the center. The outer edge surface portions of the element fall in the cylinder defined by the inner cylindrical surface of glass tube 18. A narrow, relatively deep helical groove 20 is formed in element 14 with the walls being at an acute angle with respect to each other. Filament l2 is supported at the bottom of the groove on an arcuate surface formed by rounding the apex of the V-shaped groove. The surfaces of element i4 may be thought of as generated or engendered about the axis, by a V having a rounded point or bottom, lying in a plane including the axis, and revolved about the axis while moved longitudinally along the axis. The legs of the V form the walls 22 which restrict the angle of incidence of light from the filament unto the spectral selector coating 16. This acute angle is relatively small, ordinarily a few degrees. Since the color emitted from a spectral selector coating varies markedly with the angle of incidence of the light thereon, optimum results are obtained from a spectral selector having the light rays projected exactly perpendicular thereto. Since, however, no significant light ou-tput would result if the grooves 20 were so restricted, a small angular range is purposely provided. The angle is made small enough to have essentially no effect on the true color output, and yet large enough to obtain a useable light output. This causes the output color to be that caused by an incidence angle on the coating equal to the average angle of incidence of the acute range selected for the cartridge. Thus, using presently available data on spectral selector films, and the average angle of incidence for the specific acute angle of groove Ztl for the particular cartridge involved, the output color of the cartridge can be readily determined.

It is to be understood that the multifilm spectral selector coating comprises a conventional plurality of films of selected metals applied one directly upon the other without intermediate lters. Normally, up to different layers can be applied as deemed necessary, but the total thickness is not more than about forty microinches. The coatings are usually of rare earth metals for the visible light range. Films ordinarily used for control of light in the visible region are formed by vapor deposition using magnesium fiuoride, zinc sulfide, silicon monoxide, titanium dioxide, cerium dioxide, and antimony trisulfide. These selectors have almost no absorption, and do not change characteristics even under high heating conditions, as is known. The coatings generally are of dielectric materials. The base materials for the films are usually glass, borosilicate glass or quartz. If the coating is applied to the exterior of the cylinder, the cylinder is transparent to assure passage of light at the proper angle of incidence for the light rays on the spectral selector coating. If the coating is applied to the interior of the cylinder, the tube may be translucent and not necessarily transparent since the light will already have passed through `the spectral selector, so that subsequent diffraction of the rays will not be significant to the operation. The terms transparent and translucent are intended according to their ordinary usage. T he light transmission characteristics required depend upon the necessity of impinging the light rays onto the spectral selector coating at the Controlled angle of incidence range. It is believed unnecessary to expand upon the technology of spectral selectors further. Additional technology may be obtained from several sources including Bausch & Lomb and Optical Coating Laboratories.

Particular multifilm selectors may be selected to produce any desired color. They are intended to usually produce the primary colors red, green and blue which can be combined in one lamp in this invention. The selectors `transmit only the desired spectral band width from the visual spectrum of about 400 to 700 millimicron wave length range, to produce the particular color needed. For example, currently the Bausch & Lomb red selector is identified as 90-2-600 coupled with a 90-2-540. The green is ordinarily 90-4-540 coupled with 90-2-500, and the blue is 90-1-480 coupled with 90-1-540. In each case, the first number identifies the angle of incidence, i.e. the 90 optimum angle from which the novel cartridge departs just slightly. The second number is a design designation. The third number defines a functional wave length. If `the spectral selector has a single wave length cutoff which must be defined, this third number is the wave length in millimicrons at the transmittance point on this cutoff. This, for example, holds true Vfor the blue multifilm selector which selects visible wave lengths at the blue end of the spectrum to the ultra-violet range. This holds true also for the red selector which selects wave lengths at the red end of thel spectrum to the infrared range. The green filter, on the other hand, selects wave lengths from the middle of the visible range, and possesses two cutoffs. Its third identification number then refers to the wave length at the center of the band transmitted. Ordinarily, when the films are deposited by vacuum deposition techniques, the coating material is placed in a vacuum reactor and heated until either it evaporates or sublimes. It then is allowed to condense on the translucent tube 18.

The cartridge 1t) in FIG. l may be inserted directly in a small glass envelope 13 about the size of a Christrnas tree bulb, for example as illustrated in FIGS. 5 and 6. The electrical leads 17 are connected to the ends of filament 12 and to any suitable type of socket connector 15. The leads and cartridge are supported on a suitable glass column 19. The bulb envelope is evacuated and usually filled with an inner atmosphere such as nitrogen, iodine, or other suitable substance according to conventional practice with bulbs. The small, true-color bulb can serve for decorative purposes on Christmas trees or displays, etc.

Alternatively, a group of the novel cartridges may be mounted in a larger envelope 3f) such as an opal diffuser envelope having a hemispherical lower portion as on a conventional light bulb (see FIG. 2). The cartridges 10 are all supported on a central support column 32 extending down into the hemisperical portion of the bulb from the tube base 34. The cartridges are grouped in a symmetrical pattern to produce a uniform light output from the hemispherical portion of the bulb. The opal hemispherical diffusor blends the primary color light components into a single-color, output light having even illumination from the diffusor along the axis of the bulb and the hemispherical portion thereof. This result is especially advantageous for use of the bulb with photographic enlarging and printing as mentioned hereinafter, since not only is the color exactly controllable, but also the illumination is even, the output is along the bulb axis without requiring the use of additional optical means, and the individual colors are all uniformly blended and integrated. A preferred pattern is the radial, generally circular pattern shown in FIG. 3. Independent leads 36 connect to the outer ends of the` cartridges. A larger, central, common lead 38 extends through column 32 and connects to the inner ends of the filaments. This also supports the cartridges. In the arrangement shown, the three primary colors, red, green and blue, are all represented by the cartridges. The coatings 16 are selected of appropriate spectral selector combinations to obtain the desired output color. Here there are three cartridges for red, three for green, and three for blue spaced alternately around the symmetrical pattern. The three leads to the three red cartridges are connected together in the base 34, the three leads to the green cartridges are connected together in the base, and similarly the three blue leads are connected. The tube base 34 in this exemplary structure is provided with four prongs, No. l being the return prong from common return lead 38, No. 2 being the prong electrically connected to leads to the three red cartridges, No. 3 being the prong connected to leads to the three green cartridges, and No. 4 being the prong electrically connected to leads to the three blue cartridges. Of course, there may be any number from 1 on up of the particular colors involved, but three are shown for illustration purposes. The bulb is noticeably simple in construction. It is easy to use merely by inserting it into a plug. The plug will merely have sockets 1', 2', 3 and 4 (FIG. 4) to receive the respective pins l, 2, 3, and 4 leading to the plurality of cartridges.

If all of the cartridges are provided with substantially equal electrical potential, the three primary colors can be combined to produce pure white light output composed only of the three primary colors and not colors in the spectrum. If, on the other hand, it is desired to produce any other color shade within the entire visible spectrum, either one or two of the three primary color cartridges can be varied in output intensity. Varying the primary components varies the composite output. To do this, power leads 42 to socket 40 are provided with three independent

variable transformers

44, 46 and 48 to control the electrical input to red, green and blue cartridges, respectively. By varying the output voltage from the transformers to increase one or two of the colors, the composite color can be easily and widely changed over the entire visible range of the spectrum. Although the three most common primary colors of red, green, and blue are discussed most with respect to this invention,

any three colors which, when combined, can produce white light are intended as primary colors and are included within the broader aspects of this invention. If the transformers are wound on a logarithmic pattern, the individual component output variation will be linear. If the transformers are linearly wound, the output variation will `be logarithmic.

In operation, therefore, the cartridge may be enclosed in a -small bulb envelope and supplied with electric power to produce a monocolored bulb. Alternatively, the cartridges can be placed in groups to provide a variable light source. With three primary colors in an envelope approximately the size of a conventional bulb, and with electrical suitable outlets and controls for the respective independent filaments, a single bulb can be caused to vary in color over the entire visible range in an infinitely variable manner. The attractiveness of this invention for display, decorative, or scientific purposes, is only too obvious. Any particular selected color may be easily reproduced by simply recording the values on the respective variable transformers to achieve a particular color the first time. In uses such as photographic printing and enlarging, any color may be projected on a single axis from the bulb without resorting to complex filtering techniques heretofore used, or the use of optical focusing elements. It will be obvious to those in the art, that a host of other uses, and a great number of other advantages could be cited within the principles taught. It will be obvious to those in the art that the particular construction shown may perhaps be modified physically to `suit a particular situation, while applying the inventive principles set forth herein. It is believed that this lamp and cartridge form a basic invention, and therefore the illustrated structures, although depicting the preferred forms of the invention are not to be limiting in nature, but illustrative thereof. The invention is to be limited only by the scope of the appended claims and the reasonable equivalents thereto in view of the state of the art.

I claim:

1. A lamp cartridge comprising: a source of light; a multifilm spectral selector mantle surrounding and uniformly spaced from said source; and light ray restricting means limiting the angle of incidence of light from said source on to said mantle to provide a selected spectral color output.

2. A lamp cartridge comprising: a filament adapted to be mounted in an inert atmosphere; a multifilm spectral selector mantle around said filament; and means limiting the angle of incidence of light rays from said filament onto said mantle to provide a source of controlled color output.

3. A lamp cartridge having a controlled spectral band emission, comprising: a filament arranged in an orderly pattern; a translucent housing around said filament; a multifilm spectral selector coating on said housing adapted to pass a preselected -spectral light band; and light ray alignment means supported by said housing for limiting the angle of incidence of light rays on said multifilm coating and thereby providing a controlled color output.

4. A monocolor lamp cartridge comprising: a helical filament about an axis; a support for said filament; helical means radiating from said axis and providing a limited angle range of light projection from said filament; and multifilm spectral selector means at the radiated extremity of said helical means to pass only a selected spectral range of light to create a selected color output.

5. A monocolor lamp cartridge comprising: a filament wound in a helical pattern on an elongated support having a central axis; a translucent, annular cylindrical tube spaced from said filament; a multifilm spectral selector coating on said tube; and helically-oriented, light ray limiting means radiating away from said axis and toward said tube and restricting the light from said filament incident to said coating to a specific small angular range to provide a controlled color output from said tube.

6. A lamp cartridge comprising: an elongated element having surfaces engenedered about an axis by a V lying in a plane including the axis and revolved about the axis while moved longitudinally along the axis; a helical filament supported in the groove formed by the apex portion of said V; the legs of said V and thereby the walls engendered thereby being at a small predetermined acute angle to restrict the angular range of light radiated from said filament; and a cylindrical multifilm spectral selector mantle around said filament and surface creating essentially a monocolor output from said restricted light.

7. A lamp cartridge comprising: an elongated ceramic element, the outer surface of which lies in an imaginary cylinder, and having a helical groove along its length; said groove being relatively narrow and deep; a helical filament along the bottom of said groove and adapted to project light in a narrow projection angle range out between the walls of said groove; a light transmitting cylinder around said element; and a multifilm spectral selector coating -on said cylinder to select from. the light from said filament wave lengths to produce a preselected color.

S. A lamp, comprising: an enclosing sealed envelope having electrical connections; a plurality of cartridges in said envelope and connected to respective ones of said electrical connections; said cartridges each having a multifilm spectral selector mantle adapted to select light of a preselected color from a source; a light source in each cartridge, and means restricting the angle of incidence of light from said source onto the spectral selector mantle to provide a preselected output color.

9. A lamp, comprising: an enclosing sealed envelope having electrical connections; a plurality of lamp cartridges in said envelope connected to respective ones of said electrical connections; said cartridges each having a filament wound in a helical pattern on a support along an axis; a translucent annular cylindrical tube spaced from said filament; a multifilm spectral selecting coating on said tube; and helically-oriente-d, light ray limiting means radiating away from -said axis and toward said tube restricting the light from said filament incident to said coating to a specific small angular range to provide a controlled color output from said tube.

10. A lamp, comprising: an enclosing sealed envelope having electrical connections; a plurality of lamp cartridges in said envelope and connected to respective ones of said electrical connections; said cartridges each having an elongated ceramic element, the outer surface of which lies in an imaginary cylinder, and having a helical groove along its length; said groove being relatively narrow and deep; a helical filament along the bottom of said groove and adapted to project light in a narrow projection angle range out between the walls of said groove; a light transmitting cylinder around said element; and a multitilm spectral selector coating on said cylinder to select specific wave lengths of light from said filament to produce a preselected color output.

Il. A lamp, comprising: an enclosing sealed envelope having electrical connections; a plurality of lamp cartridges in said envelope and connected to respective ones of said electrical connections; said cartridges each having an elongated element having a surface formed about an axis by a V lying in a plane including the axis and revolved about the axis While moved longitudinally along the axis; a helical filament supported in the groove formed by the apex of said V; the legs of said V and thereby the walls engendered thereby being at a small predetermined acute angle to restrict the angular range of light radiated from said filament; and a cylindrical multifilm spectral selector mantle around said filament and surface creatingh essentially a mono-color output from said restricted ligl t.

12. A lamp, comprising: an enclosing sealed envelope having electrical connections; a plurality of lamp cartridges in said envelope and connected to respective ones of said electrical connections; said cartridges each having a filament wound in a helical pattern on a support along an axis; a transluc-ent, cylindrical tube spaced from said filament; different multifilm spectral selector coatings on said tube causing a plurality of output colors; helicallyoriented, light ray limiting means radiating away from said axis and toward said tube and restricting the light from said filament incident to said coatings to a specific angular range to provide the controlled color from each tube; and a variable electrical input control means for cartridges of different colors enabling the composite overall lamp color to be varied by variation of the electrical input to different color cartridges.

13. A lamp, comprising: an enclosing sealed envelope having an inert atmosphere and electrical connections; a plurality of symmetrically-arranged lamp cartridges in said envelope and connected to respective ones of said electrical connections; said cartridges each having an elongated ceramic support element, the outer surface of which lies in an imaginary cylinder, and having a helical relatively narrow and deep V-shaped groove along its length; the walls of said groove being at a small acute angle; a helical filament along the bottom of said groove and adapted to project light in a narrow projection angle range out between the walls of said groove; a light transmitting cylinder around said element; multifilm spectral selector coatings on respective cylinders to select pre determined wave lengths from said light from said filaments to form a plurality of preselected output colors; and a variable input electrical control means for cartridges of different colors enabling overall lamp output color variation by variation of the components thereof.

14. A lamp, comprising: an enclosing envelope having electrical connections; a plurality of lamp cartridges in said envelope and connected to respective ones of said electrical connections; said cartridges each having an elongated element having surfaces formed about an axis by a V lying in a plane including the axis and revolved about the axis while moved longitudinally along the axis; a helical filament supported in the base of the groove formed by the point of said V; the legs of said V and thereby the walls engendered thereby being at a small predetermined acute angle to restrict the angle range of light radiated from said filament; a cylindrical multifilm spectral selector mantle around said filament and surfaces selecting wave lengths to create essentially a monocolor from said restricted light; different cartridges having diferent colors; and variable input control means for the cartridges of different colors enabling overall lamp color variation by variation of the components thereof.

15. A lamp cartridge comprising: a source of light; a spectral selector mantle capa-ble of selecting a limited wave length range of light from light impinged thereon at a controlled angle of incidence thereto, and surrounding and uniformly spaced from said source; and light ray restricting means limiting the angle of incidence of light from said source on to said mantle to provide a selected color output.

16. A lamp, comprising: an enclosing sealed envelope having elect-rical connections; a plurality of cartridges in said envelope and connected to respective ones of said electrical connections; sa-id cartridges each having a multifilm spectral selector mantle adapted to select light of a preselected color from a source; thereby providing different colors from the cartridges; a light source in each cartridge; means restricting the angle of incidence of light from said source onto the spectral selector mantle to provide a preselected output color; said cartridges being arranged around an axis of light output; and hemispherical opal difiusor means on said axis in the path of the output light of the different colors to blend lsaid colors into a single color output with even illumination along said axis.

References Cited by the Examiner UNITED STATES PATENTS 1,649,975 ll/l927 Parks 313-33 2,007,945 7/1935 Harding 313-271 X 2,097,679 11/1937 Swanson 313-222 X 2,412,496 `12/1946 Dimmick 88--105 2,545,896 3/1951 Pipkin 313-116 FOREIGN PATENTS 746,249 3/1933 France.

778,438 7/1957 Great Britain.

834,087 5/1960 Great Britain.

GEORGE N. WESTBY, Primary Examiner.

Claims

12. A LAMP, COMPRISING: AN ENCLOSING SEALED ENVELOPE HAVING ELECTRICAL CONNECTIONS; A PLURALITY OF LAMP CARTRIDGES IN SAID ENVELOPE AND CONNECTED TO RESPECTIVE ONES OF SAID ELECTRICAL CONNECTIONS; SAID CARTRIDGES EACH HAVING A FILAMENT WOUND IN A HELICAL PATTERN ON A SUPPORT ALONG AN AXIS; A TRANSLUCENT, CYLINDRICAL TUBE SPACED FROM SAID FILAMENT; DIFFERENT MULTIFILM SPECTRAL SELECTOR COATINGS ON SAID TUBE CAUSING A PLURALITY OF OUTPUT COLORS; HELICALLYORIENTED, LIGHT RAY LIMITING MEANS RADIATING AWAY FROM SAID AXIS AND TOWARD SAID TUBE AND RESTRICTING THE LIGHT FROM SAID FILAMENT INCIDENT TO SAID COATINGS TO A SPECIFIC ANGULAR RANGE TO PROVIDE THE CONTROLLED COLOR FROM EACH TUBE; AND A VARIABLE ELECTRICAL INPUT CONTROL MEANS FOR CARTRIDGES OF DIFFERENT COLORS ENABLING THE COMPOSITE OVERALL LAMP COLOR TO BE VARIED BY VARIATION OF THE ELECTRICAL INPUT TO DIFFERENT COLOR CARTRIDGES.