Laser protection goggles

The invention is a laser ray eye protection device comprised of a laser detector, voltage controlled lens or lenses, and related interconnecting circuitry. The lenses remain in the normally transparent state until a laser ray is sensed by the detector which energizes the lenses into a state of opacity by the interconnecting circuitry. The invention may take on numerous specific embodiments. Various partial modifications and combinations thereof are described.

CROSS REFERENCE TO RELATED PATENTS AND PATENT APPLICATIONS 
The following U.S. patents and pending patent application having same named 
inventor as the present application, are related to the present 
application in that a voltage controlled lens is utilized to provide 
dynamic scattering of light: 
U.S. Pat. No. 4,021,935, 
U.S. Pat. No. 4,106,217, 
U.S. Pat. No. 4,152,846, and 
U.S. patent application, Ser. No. 343,017, filed Jan. 26, 1982. 
BACKGROUND OF THE INVENTION 
The present invention relates to a pair of glasses worn by a person for eye 
protection against damage by laser rays, and more particularly relates to 
a liquid crystal lens configuration in combination with a laser radiation 
detector for blocking radiation from passing through the lens preventing 
eye injury. 
The term, laser, refers to a process whereby a collimated beam of 
electromagnetic rays is amplified into a very narrow wavelength spectrum, 
having a high intensity. The intensities emitted pose a tremendous eye 
hazard. Despite purposeful avoidance of the laser rays, the rays may be 
received inadvertantly by the eye either directly or from reflection. 
Theoretically, laser rays can be made from any part of the electromagnetic 
spectrum--from the lowest frequency (radio waves) to the highest frequency 
(gamma waves). Currently, laser rays are made from the non-visible 
infrared and visible portions of the electromagnetic spectrum. It is 
expected that laser rays will be made from the ultraviolet portion of the 
spectrum in the near future. 
Heretofore, eye protection from laser rays has been provided by a pair of 
goggles having a permanently darkened lens providing constant visual 
restriction. Such prior art goggles are sensitive to a single frequency of 
laser radiation. Different goggles must be used for each frequency 
encountered. Further, night time protection is unafforded by such prior 
art goggles due to the inherent visual restrictions accompanying the 
goggles. 
It would be highly desirable to provide a device suitable for eye 
protection from laser rays without the accompanying visual restriction 
when laser rays are not present. Such protection from laser rays should be 
provided in general whether used for commercial, industrial, medical, 
military, or other purposes, and from laser rays of a broad 
electromagnetic spectrum. Particularly, it is desirable to provide such a 
device which not only would be effective in protecting the eyes from laser 
rays which presently exist, but also to provide the same adequate 
protection from laser rays of other wavelengths which presently are not 
used. 
It is therefore an object of the present invention to provide an improved 
laser eye protection device. 
It is yet another object of the present invention to provide a laser eye 
protection device which is responsive to a broad spectrum of laser 
frequencies. 
It is yet another object of the present invention to provide a pair of 
laser protection goggles which may be used for night time protection. 
It is a further object of the present invention to provide a laser 
protection device that is sensible and convenient to wear and which will 
not interfere with ordinary activity. 
These and other objects of the present invention will become apparent from 
the following detailed description of the preferred embodiment. 
SUMMARY OF THE INVENTION 
The invention is a device for protecting the eyes from laser radiation. 
Protection is provided by means of a normally transparent voltage 
controlled lens which is switchable to an opaque state. A detector senses 
laser radiation and switches the lens to its opaque state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, a voltage controlled lens 11 is set in a frame 
13. The lens has a normally transparent state of light transmissiveness 
and is switchable to an opaque state for scattering light. The outer 
perimeter 15 of lens 11 extends within frame 13 as shown. The frame may be 
adapted to be held in front of the viewer's eyes by suitable means. 
A primary detector 17 is constructed from an array of ambient 
omnidirectional photocells 19 and is positioned relative to frame 13 for 
sensing a laser beam moving onto lens 11. The photocells are arranged 
along a path 23 encompassing perimeter 15 of the lens, being equally 
spaced from one another. The distance between each photocell 19 is 
dependent on the minimum diameter of a laser ray bundle expected to be 
encountered by the wearer of the lens. 
As shown in FIG. 2, photocells 19 are embedded within frame 13 such that 
their operational axes are substantially perpendicular to the plane of 
lens 11 which they are guarding. The photocells are conventional and are 
sensitive to any wavelength of laser intensity. When laser ray bundle "A" 
sweeps across the lens (as indicated by direction arrows 24), the ray 
bundle first crosses the guarded path 23 of the photocells prior to 
impinging lens 11. One or more of photocells 19 is actuated thereby 
causing the normally transparent lens to switch to its opaque state. The 
opaque state of the lens blocks the laser from passing through the lens to 
the wearer's eye. 
Lens 11 is a conventional liquid crystal lens being formed of a transparent 
liquid crystal layer 25 which is sandwiched between a pair of flat panes 
27, 29 of transparent solid material. The inner surfaces of the flat panes 
are each coated with a very thin layer of a transparent electrically 
conductive electrode. An alignment coating of transparent material is 
laminated over each electrode coating aligning the liquid, as described 
with reference to FIG. 14. An applied voltage to the electrode coatings 
will cause an electric current to flow through the liquid crystal layer 
causing a turbulence within the crystal making the lens structure opaque 
to light. This is referred to as a dynamic scattering of light. 
The lens is switched to its opaque state by means of switching circuitry 
31. Circuitry 31 includes a conventional voltage waveform generator for 
applying a waveform of a particular oscillating frequency across lens 11. 
In its opaque state, lens 11 scatters and breaks up laser ray bundle "A" 
so that it does not pose an eye hazard. When laser ray bundle "A" moves 
outside of the perimeter of primary detector 17, either by continued 
sweeping motion of bundle "A" or by the wearer of the device 10 turning 
his head so as to cause bundle "A" to move outside of the perimeter of 
primary detector 17, circuitry 31 disconnects the voltage waveform from 
lens 11 returning the lens to its normally transparent state. 
Circuitry 31 monitors actuation of photocells 19, such that the actuation 
of a single photocell prompts circuitry 31 to apply the voltage waveform 
to lens 11. Where a pair of lenses are used as shown in FIG. 7, circuitry 
31 may control the lenses independent of one another. 
Referring to FIG. 13, photocells 19 are connected in two groups 47, 49 
around each lens 11 of a dual lens system. A voltage source 51 places an 
output voltage across leads 53, 55 for attempting to actuate a light 
emitting diode 57. Each of photocells 19 of group 47 are electrically 
connected in parallel and connected between lead 53 and the anode of diode 
57. The actuation of any one of photocells 19 by the laser beam closes the 
circuit path between lead 53 and diode 57 causing the diode to light. 
Diode 57 serves as the switching portion of an optocoupler (not shown) 
which cause the liquid crystal lens to be energized to its opaque state 
whenever diode 57 is lit. As understood, the opto-isolator merely serves 
to connect the voltage generator across the electrode coatings of lens 11. 
Group 49 of photocells 19 are similarly connected in parallel between lead 
53 and diode 57 but via a blocking diode 59. Group 49 serves to actuate 
the lens 11 whenever one of its photocells is actuated by the laser beam. 
However, unlike group 47, group 49 also actuates the right lens 11. As the 
laser sweeps from left to right, group 47 is actuated first causing only 
the left lens to actuate to its opaque state. As the laser moves into 
group 49, the left lens remains opaque and the right lens is actuated to 
its opaque state. As the laser moves farther right on the right lens, the 
left lens clears. 
A similar pair of groups 61, 63 of photocells 19 operate in a manner 
similar to groups 47, 49. Light emitting diode 65 and blocking diode 67 
operate similar to diodes 57, 59. The two groups 49, 61 are connected 
together by leads 69, 71 such that each group 49, 61 serves to actuate 
both right and left lenses. The blocking diodes 59, 67 serve to prevent 
groups 47, 63 from actuating their non-associated right and left lens, 
respectively. 
Referring to FIG. 3, in the unlikely event that the laser ray bundle does 
not move laterally across primary detector 17, as in the preceding 
discussion, but rather is so aimed as to constitute a direct hit (bundle 
"B") upon the voltage controlled lens, there is provided a secondary 
detector 33 constructed of a second array of like photocells 35 mounted by 
suitable means behind lens 11. Upon sensing the splash of bundle "B" upon 
the lens, secondary detector 33 in like manner as detector 17 causes lens 
11 to transition to its opaque state. The electrical switching of 
circuitry 31 is responsive to an electrical signal from either of 
detectors 17 or 33. 
As understood, the time of switching of the lens is a factor in the 
prevention of eye injury. The sweeping of bundle A as shown in FIG. 2 is 
very much slower than the direct hit of bundle B in FIG. 3. The detector 
33 serves to opaque the lens after the front end of bundle B has passed 
through the lens. The size, intensity and angle of lens impingement of 
bundle B determines the effect, if any, of the front end of a direct hit 
by bundle B. 
Referring to FIG. 4, voltage controlled lens 11 may be comprised of more 
than one cell. Whereas FIGS. 2 and 3 depict a single cell comprised of one 
liquid crystal layer 25, FIG. 4 depicts multiple cells comprised of 
alternate laminations of transparent solid material 37 and normally 
transparent liquid crystal material 39. As previously indicated, when a 
voltage is applied to the liquid crystal material, the lens changes from a 
normally transparent state to an opaque state. The degree of opacity is 
dependent on the thickness of the liquid crystal material. However, the 
response time required to transition from one state to another increases 
with the thickness of the liquid crystal material. For this reason cells 
are stacked as in FIG. 4, in order to provide a decrease in response time 
for the overall thickness of the lens system. 
FIG. 5 depicts one of many possible specific embodiments of the invention 
in which a single lens 11 is mounted in a mask 40. Photocells 19 are 
positioned around the perimeter of the lens as shown. 
Having reference to FIG. 6 there is depicted another partial modification 
wherein voltage controlled lens 11 has upper and lower segmented areas 41, 
43. Upper segment area 41 has been shaded to show that it is in the opaque 
state while lower segment area 43 remains clear. The lens can be segmented 
by using separate electrode coatings on respective segments 41, 43. 
Detector 17 is wired so that when a laser ray bundle crosses the perimeter 
of the lens only the segment area 41 or 43 receiving the laser ray bundle 
is energized to the opaque state thereby providing uninterrupted 
visibility through the unaffected segment area. Many other shapes and 
numbers of segment areas are possible, as will suggest itself. 
The wiring of the two segments 41, 43 for separate actuation may be similar 
to that of FIG. 13. Two groups similar to groups 47, 49 of photocells may 
control separate lens segments. Two light emitting diodes 57 may be used, 
one for each lens segment. One group of photocells actuates one diode 57 
of an opto-coupler which switches the voltage waveform onto one of the 
lens segments; the other group of photocells actuates the other diode 57 
of another opto-isolator which switches the voltage waveforms to the other 
lens segment. 
Having reference to FIGS. 7 and 8, another partial modification is depicted 
wherein more than one voltage controlled lens 11 is incorporated into each 
laser ray eye protection device. Many other designs having multiple 
voltage controlled lenses 11 are possible. 
As shown in FIGS. 7 and 8, each voltage controlled lens 11 has around its 
perimeter its own respective detector 17 to thereby provide for 
energization to the opaque state only that lens 11 or those lenses 11 
which encounter a laser ray bundle, and therefore results in uninterrupted 
visibility through any unaffected lens 11. 
Having reference to FIGS. 9 and 10, another partial modification is 
depicted wherein a standard transparent solid material 37 of FIG. 9 is 
replaced by a non-standard transparent solid material 45 in FIG. 10, so 
that visual correction, when needed, may be incorporated into the 
invention thus making the overall eye protection package more lightweight 
and compact for those who wear glasses. Many other designs and 
arrangements having corrective lenses 45 incorporated into the invention 
are possible. 
Having reference to FIG. 14, alignment coatings, as discussed above, are 
indicated by close parallel lines on front views of superimposed glass 
panes 71, 73, 75. Alignment coating 77 is formed on pane 71 and is 
perpendicular to alignment coating 79 formed on the left face of pane 73. 
Liquid crystal (not shown) is positioned between panes 71 and 73 and 
between panes 73 and 75. Alignment coating 81 is positioned on the right 
face of pane 73 (the figure illustrates the two coatings 79, 81 on the 
same pane) and is perpendicular to alignment coating 83 formed on pane 75. 
The three panes 71, 73, 75 may be said to form two cells which are bounded 
by alignment coatings 79, 81. As shown, the two alignment coatings 79, 81 
are at approximately 45.degree. to each other. As more cells are added, 
the alignment coatings bounding the cells may be set at various 
progressive angles. For example, the first two cells at 0.degree. and 
30.degree., the next cell set at 60.degree., the next cell set at 
90.degree. and so on to 330.degree.. This arrangement of various angles of 
the alignment coatings aids in blocking laser bundles which strike the 
lens at an angle. Thus for maximum opacity, alignment coatings for each 
cell are placed at 90.degree. to each other. When cells are stacked, 
bounding alignment coatings are placed at various angles to increase 
scattering of light. 
The alignment coating is a transparent coating which is put over the 
underlying transparent electrode coating. When sufficient voltage is 
applied to the liquid crystal lens, the alignment coatings serve to align 
the molecules of the liquid material so that on opaque effect (dynamic 
scattering) is apparent. 
Having reference to FIGS. 15 and 16, there is depicted another partial 
modification wherein the entire perimeter of the lens is guarded by an 
alternate dectector 85 comprised of a single photocell 87 imbedded in a 
transparent or translucent frame 89. Depending upon the length of the 
perimeter perhaps in some cases more than one photocell may be needed. 
When the frame is transparent, it is necessary to roughen the finish in 
order to provide a light scattering means. If the frame is translucent, a 
roughened finish is sometimes helpful but not as necessary since 
translucent material has an inherent light scattering property. 
Preferably, the light carrier is injection molded from acrylic. 
In FIGS. 15 and 16, whenever a light bundle of laser intensity strikes any 
part of frame 89, some of the bundle is transmitted and scattered 
throughout the frame, thereby actuating detector photocell 87 which, in 
turn, signals the lens to change to its opaque state. 
FIGS. 11 and 12 are yet further possible specific embodiments of the 
invention which merely serve to illustrate the fact that the invention, 
per se, is not limited to any one or even a few embodiments, but the 
invention which is comprised of detector means, voltage controlled lens or 
lenses, and associated conventional electrical components, has in fact 
numerous designs, structures and arrangements which directly fall within 
the spirit and scope of the invention and appended claims. 
Having thus described, the invention, what is claimed as new and desired by 
Letters Patent of the United States is set forth in the following claims.