Amplifier assembly for electromagnetic radiation, preferably in the actinic spectrum

There is disclosed a novel light transmitting assembly comprised of a screen assembly having a plurality of generally conically-shaped repeater orifices wherein an optical fiber of an optical fiber bundle is disposed within each repeater orifice and wherein the repeater orifices are enclosed with an optical fiber array disc and wherein the optical fiber bundle is positioned between the screen assembly and a frame member for displaying thereon electromagnetic radiation preferably in the actinic range.

FIELD OF THE INVENTION 
This invention relates to transmission of electromagnetic radiation and 
more particularly to a novel transmitting assembly for electromagnetic 
radiation preferably in the actinic spectrum and method of manufacturing 
same. 
BACKGROUND OF THE INVENTION 
The use of image intensifiers has found many usages, including observations 
at low light levels, e.g. at night, or to create a visible image from 
electromagnetic radiation invisible to the human eye. An image intensifier 
tube is generally comprised of a sealed cylindrical enevelope having its 
one end closed by an entry window on the inner surface of which a 
photo-sensitive, electron emitting layer in electrical contact with, and 
enclosed by, a substantially circular, electrically conductive rim. The 
outer end of the cylindrical envelope is closed by an exit window on which 
an anode in the form of a phosphor screen is deposited. Means is provided 
for focussing a beam of electrons released from the photosensitive, 
electron emitting layer by incident radiation and comprising at least a 
cathode flange mounted around the substantially circular electrically 
conductive rim. The cathode flange is sealed by fritting to the entry 
window and is electrically connected to an electrically conductive, 
cylindrical member constituting part of the envelope. The image 
intensifier further comprised a source of voltage located outside the 
envelope having its positive terminal connected to the anode to supply 
voltages to the anode and a focussing means. An electric field formed 
within the enevelope focusses the beam of electrons released from the 
photosensitive, electron emitting layer onto the anode of the image 
intensifier device. 
OBJECT OF THE INVENTION 
An object of the present invention is to provide a novel light amplifier. 
Another object of the present invention is to provide a novel light 
amplifier obviating additional energy input. 
Still another object of the present invention is to provide a novel light 
amplifier for enlarging images. 
Yet another object of the present invention is to provide a novel light 
amplifier of improved lumins efficacy with reduced energy expenditure. 
A further object of the present invention is to provide a novel light 
amplifier to permit lumination at a point remote from the light source. 
A still further object of the present invention is to provide a novel light 
amplifier. 
SUMMARY OF THE INVENTION 
These and other objects of the present invention are achieved by a light 
transmitting assembly comprised of a screen assembly having a plurality of 
generally conically-shaped repeater orifices wherein an optical fiber of 
an optical fiber bundle is disposed within each repeater orifice and 
wherein the repeater orifices are enclosed with an optical fiber array 
disc and wherein the optical fiber bundle is positioned between the screen 
assembly and a frame member for displaying thereon electromagnetic 
radiation preferably in the actinic range.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now to the drawings, and in particular FIG. 1, there is 
illustrated a novel light amplifier, generally indicated as 10, comprised 
of a screen assembly, an optical fiber bundle, a frame member and a light 
source, generally indicated as 12, 14, 16 and 18, respectively. The screen 
assembly 12 is formed of glass or a plastic material, such as 
polyethylene, polypropylene or the like, preferably a thermoplastic 
material responsive to ultrasonic radiation. The screen assembly 12 may be 
dimensioned to fit any desired broadcast system e.g. rectangular shape for 
viewing images, circular shape for replacement of a traffic signal lens, 
etc., as will become clear to one skilled in the art. Thus, a rectangular 
screen assembly 12 for enlarging images may range from 2 to 3 inches in 
width and height to as large as 40 to 50 feet, or greater. The thickness 
of the screen assembly 12 generally ranges from 50 mm to 16 inches, with 
preferable thickness being determined by end usage and processing 
requirements, as more fully hereinafter discussed. 
To form the screen assembly 12, a screen substrate 20 of predetermined size 
and thickness is first subjected to an operation to form a plurality of 
conically-shaped orifices 22 of a diameter from 10 mm to 10 inches, 
referring particularly to FIGS. 3 to 4. In view of the size and shape of 
the orifices and subsequent processing considerations, it is generally 
desirable to form the orifices in lines and rows, although random 
orientation will achieve the same result. Each conically-shaped orifice 22 
may be formed using laser techniques, such as a type of laser machine 
manufactured and sold by International Business Machine and utilizing 
laser vaporization techniques. 
Accordingly, referring particularly to FIG. 2, the screen substrate 20 is 
subjected to initial laser fusion, drilling or casting to form 
cylindrically-shaped holes 24 through the screen substrate 20. Thereafter, 
laser fusion is effected about successively larger diameters increments of 
from 1 to 10 microns and in horizontal steps of from 1 to 10 microns to 
remove successively larger cylindrically-shaped portions of the screen 
substrate 20, referring particularly to FIG. 3 to eventually form the 
conically-shaped orifices 22 comprised of a plurality of stepped ledges. 
FIGS. 2 and 3 schematically illustrate formation of the stepped 
conically-shaped orifice 22, it being understood that such FIGS. 2 and 3 
exaggerate stepping, and that in actuality successive laser radiation is 
effected at as hereinabove described increasing diameters and longitudinal 
levels of from 1 to 10 microns. 
FIG. 4 is a front view of a portion of the screen substrate 20 after 
formation of the lines and rows of the orifices 22. Orifice density is in 
the range of from 50 to 10.sup.-2 orifices per square inch with orifice 
size being determined by screen assembly usage. Generally, the diameter of 
orifice at the light emitting surface of the screen assembly 12 will not 
be greater than about 10 times the diameter of the initial hole 24 or of 
the optical fiber 26. 
Once the plurality of orifices has been formed in the screen substrate 20, 
the surfaces of the orifices 22 are coated with a light reflecting 
material, such as aluminum, silver, gold or the like material, using for 
example, vapor deposition techniques or the like. Thereafter, respective 
optical fibers 26, referring to FIG. 5, of the optical fiber bundle 14 are 
inserted into each hole 24 in a base portion of the orifice 22 in the 
substrate 20 and is connected therein, such as by plastic adhesives, 
electromagnetic radiation, heat or the like technique to insure totality 
of sealed integrity. 
Such process is repeated until all of the optical fibers 26 constituting 
the optical fiber bundle 14 are inserted into respective holes 24 of the 
plurality of conically-shaped orifices 22. It will be appreciated by one 
skilled in the art that for light amplification, per se, random 
orientation of the optical fibers 25 within the screen assembly 12 with 
regard to the frame 16 is permissible, whereas for image amplication or 
reproduction that the optical fibers 26 of the optical fiber bundle 14 
should be aligned or oriented with respective lines and rows of the 
optical fibers 26 in the frame member 16. 
After connection of the optical fibers 26 into the plurality of 
conically-shaped orifices 22, the conically-shaped orifices 22 are filled 
with a liquid medium, such as distilled water or the like. The liquid 
medium may be any clear liquid exhibiting the desired refractive indexes 
to insure sharply defined light impulses. 
Once the orifices 24 are filled with the liquid medium, the orifices 22 are 
enclosed by an optical fiber array disc 28, referring to FIG. 5, fitted 
and sealed within the orifices 22, such as by a liquid resin, again in a 
manner to insure sealed integrity thereby forming repeater orifices or 
members. Other techniques for sealing the optical fiber array disc 28 
within each orifice 22 may be used. The optical fiber array disc 28 is 
essentially an optical fiber bundle comprised of a base portion 30 and a 
plurality of outwardly extending optical fibers 32 of a diameter of from 
10 to 20 microns. The diameter of the optical fiber array disc 28 is 
determined by a largest diameter of the conically-shape orifice 22 
together with an appropriate adhesive to contain the liquid medium 
therein. 
The optical fibers 26 forming the optical fibers bundle 14 are generally of 
the multimode light guide type comprised of a core surrounded by a 
cladding of a lower refractive index material. Typically, cores of such 
multimode light guides are of a diameter of from 100 .mu.m to 0.5 inches 
with a cladding of from 1 to 2 mm. Since such light guides are capable of 
light transmission for great distances, the length of the optical fiber 
bundle 14 may easily be selected with regard to location of the source of 
light and the specific application. The ends of the optical fibers 26 
opposite the ends positioned in the screen substrate 20 are disposed in 
the frame number 16 with ends thereof polished in a manner known to one 
skilled in the art. 
FIGS. 6 and 7 illustrate the frame member 16 of the optical fiber bundles 
14 in the form of a rectangle. It will be understood that the screen 
assembly as well as the optical fiber frame member 16 may be circular, 
elliptical, etc. For light amplification, the screen assembly 12 and 
optical fiber frame member 16 need not be of like geometric configuration. 
Similarly, while the repeater orifices 22 are disclosed as being 
conically-shaped and formed of a plurality of concentrically-formed steps, 
the repeater orifices may take other geometric forms, such as that of a 
hexagon, square, etc. For image reproduction, each optical fiber 26 
disposed in the frame member 16 is aligned within lines and rows of 
respective orifices 22 in the screen assembly 12, such that the lines and 
rows of the optical fibers 26 in the frame member 16 correspond to like 
lines and rows of optical fibers placement in the screen assembly 12. 
The light image member 18 may be a slide projector, or movie projector, a 
light bulb, or like light and/or image source.