Variable transmission light polarizing lens assembly

A sealed, polarizing lens assembly including a frame, a first light polarizing lens element, a second light polarizing lens element superimposed with the first lens element and rotatable in relation to the first lens element. The frame and the first element define a sealed chamber in which the second element is entirely enclosed and rotatable relative to the first pair of elements. Means for rotating the second internal element in the sealed chamber relative to the first pair of elements are provided. In one form the means for rotating the internal element in the seal chamber comprise a sealed gearing mechanism with user-accessible external actuators. The sealed, easily-adjusted lens assembly of the invention prevents contamination of internal lens surfaces by dust and moisture, for example. The seal chamber can also be provided with a fluid or gas with desired optical or thermal barrier characteristics.

TECHNICAL FIELD 
The invention relates generally to lenses comprising superimposed light 
polarizing elements which are selectively rotatable to vary the amount and 
wave lengths of light transmitted through the lenses. 
BACKGROUND ART 
Spectacles having superimposed polarizing lenses are well known. U.S. Pat. 
No. 2,005,426 discloses sunglasses having two superimposed polarized 
lenses mounted in conventional spectacle frames. One of the two lenses is 
fixed in relation to the frame, while the other is rotatable in relation 
to the first lens. In this fashion, the pair of polarized lenses for each 
eye may be adjusted in relation to one another, thereby regulating the 
light transmission through the lens pair. 
U.S. Pat No. 4,119,369 issued to Vaitok Eloranta and Benjamin Ruggles 
describes superimposed pairs of light polarizing elements, one pair of 
such elements being fixed and another pair being rotatable with respect to 
the fixed pair to provide variable light transmission. In this device, the 
lens pairs are superimposed in a single eyeglass frame, and the rotating 
lenses are interconnected by a tie bar to insure nearly identical axial 
rotation of the rotating elements. 
U.S. Pat. Nos. 4,592,262 and 5,210,552 disclose pairs of polarized lens 
elements which are synchronized in rotation through a centrally mounted 
gear. Both of these devices comprise separate lens elements, one 
superimposed over the other. 
Further, it is known that ophthalmic lenses may be designed incorporating 
fluids for the purposes of creating variable power lenses. See, for 
example, U.S. Pat. Nos. 4,913,536 and 5,124,734. The benefit of the 
application of this technology to superimposed polarizing lenses is the 
reduction of surface reflection and refraction resulting from the 
incidence of light on multiple surfaces in superimposed lenses. 
SUMMARY DISCLOSURE OF INVENTION 
None of the prior art has directly addressed the problem of lens 
contamination and the associated cleaning requirement for lenses having 
superimposed elements. The existing technology dictates the disassembly of 
the lens elements to effect cleaning. 
The present invention utilizes a sealed lens assembly, which, in one 
embodiment, may be fluid-filled, to address the foregoing shortcomings of 
the existing art. 
In general, the invention is achieved with a sealed lens assembly having a 
frame, a first light polarizing lens element, and a second light 
polarizing lens element superimposed with the first lens element and 
rotatable in relation to the first lens element to affect light 
transmission through the lens elements. A first lens element comprises a 
sealed chamber having a front pane and a rear pane joined by a continuous 
wall section of the frame to define the chamber. The second lens element 
comprises a transparent element disposed entirely within the sealed 
chamber for rotation therein. The inventive lens assembly further includes 
means for rotating the second lens element in axial relationship to the 
first lens element. 
The second lens element is adjusted by the user via external actuation 
means. Adjustments are transmitted to internal drive means within the 
sealed chambers by sealed force-transmitting means to rotate the second 
lens elements, for example internal polarized lenses. 
In one embodiment the inventive lens assembly is employed in a pair of 
light polarizing spectacles in which a pair of the lens assemblies are 
operated by a single, user-accessible rotation mechanism actuated from the 
exterior of the sealed chambers. 
In further embodiments the means for rotating the second (internal) lens 
elements in the sealed chambers comprise gear or belt-drive mechanisms. 
The external actuating means can include indicia indicating the degree of 
adjustment. 
In another embodiment of the invention the front pane of the sealed lens 
assembly is formed from a transparent material, while the rear pane of the 
lens assembly is a polarizing material. The internal lens element 
rotatable within the chamber defined by the front and rear panes also 
comprises a polarizing material which cooperates with the polarizing rear 
pane to affect light transmission through the lens assembly when the 
internal lens element is rotated.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
FIG. 1 is a suitable starting point for discussion of the overall concept 
of the invention. The invention, by way of example, is shown incorporated 
into a pair of spectacles. Such spectacles, conventional in many respects, 
are defined by a spectacle frame 6 having a nose piece 8 and ear pieces 
10. The structure of the individual lens assemblies 11, corresponding to 
the left and right eyes of the wearer, is seen in further detail in FIGS. 
2 and 3. Each lens assembly 11 comprises a sealed hollow chamber 12 
defined by rear and front frame portions 6a, 6b forming a continuous wall 
4. Rear frame 6a holds a front pane 16 and front frame 6b holds a rear 
pane 14. In the preferred embodiment, front pane 16 is formed from a 
transparent material, while rear pane 14 is a polarizing material. When 
the front pane, wall section and rear pane are assembled, they define 
hollow chamber 12 containing internal lens element 56. 
Internal lens element 56 preferably comprises a light transmissive 
polarizing element, and is provided with a driven gear 60. The diameter of 
internal lens element 56 is selected to insure a relatively precise fit of 
internal lens element 56 relative to the frame wall within chamber 12. An 
opening 13 is formed in rear pane 14 to accommodate a shaft 40. An o-ring 
50 is disposed about the circumference of the shaft opening 13 to provide 
a fluid-tight seal between chamber 12, rear pane 14 and rotating shaft 40. 
External drive gear 42 is secured to shaft 40 outside chamber 12, and the 
shaft 40 is inserted through o-ring 50 previously mounted around the shaft 
opening 13. Internal drive gear 44 is mounted to the opposite end of 
rotating shaft 40 in chamber 12, such that rotation of external drive gear 
42 results in simultaneous rotation of shaft 40 and internal drive gear 
44. Internal drive gear 44 engages driven gear 60 affixed to internal lens 
element 56. In this fashion, rotation of external drive gear 42 is 
transmitted as rotational motion affecting the rotational position of 
internal lens element 56 in chamber 12 relative to panes 14, 16. 
In the preferred embodiment, each lens assembly 11, chamber 12 and internal 
lens element 56 constitute a sealed unitary combination lens assembly 
whereby the interior chamber 12, as defined by the inside surface of pane 
14, the inside surface of pane 16 and the inner surface of the wall 4 
defined by frame portions 6a, 6b constitute a sealed unit substantially 
resistant to contamination. Accordingly, chamber 12, the interior surfaces 
of panes 14, 16 and both surfaces of internal lens 56 remain relatively 
free of outside contaminants. 
A main gear 52 is pivotably attached to a pivot 54 affixed to nose piece 8. 
The diameter of main gear 52 is selected to effect engagement of the teeth 
of main gear 52 with the teeth of external drive gears 42 on each lens 
assembly 11. A gear enclosure plate 43 is provided with stop 53 which 
limits the rotational arc of main gear 52 in relation to the nose piece 8. 
Gear enclosure plate 43 attaches to nose piece 8 to partially enclose 
gears 52 and 42. This rotational limitation is provided to insure that 
internal lens elements 56 are rotationally limited to an arc of 
approximately 90 degrees. Second stop 55 on main gear 52 engages stop 53 
to affect this limitation in rotation. 
Referring now to FIGS. 3 and 4, the detailed interaction of the internal 
lens element 56, driven gear 60, internal drive gear 44, external drive 
gear 42 and main gear 52 is as follows. Main gear 52 is pivotably mounted 
to pivot 54, which, in turn, is secured to nose piece 8. The teeth of main 
gear 52 engage the teeth of external drive gear 42 which is fixed to 
rotating shaft 40. Internal drive gear 44 is likewise fixed to rotating 
shaft 40. As main gear 52 is rotated through its previously defined arc, 
external gear 42 and internal gear 44 follow main gear 52 in rotation, 
thereby driving driven gear 60 affixed to internal lens element 56. As 
internal lens element 56 rotates in relationship to the pane 16 in chamber 
12, the polarizing effect of the two lenses results in a variation of the 
light transmissibility through the lens assembly 11. 
As shown in FIG. 4, main gear 52 can be provided with indicia showing the 
degree of rotation of internal lenses 56, for example visible though an 
aperture 9 in the frame. This gives the user a repeatable setting for the 
desired polarizing effect. 
The sealed nature of each lens assembly protects chamber 12 and internal 
lens element 56 rotating therein from contaminants such as moisture and 
dust. In a preferred mode of the invention, chamber 12 is hermetically 
sealed and filled with a fluid or gas having desirable thermal or optical 
properties. Water or dust-resistant sealing will be suitable for some 
purposes, depending on the intended use. 
In the preferred embodiment, the internal lens element 56 and rear pane 16 
are selected from the class of linear or circular polarizing materials. 
Linear polarizers transmit only linearly polarized light, and circular 
polarizers transmit only right-handed or left-handed polarized light. The 
polarizers may be neutral or tinted. With a tinted polarizer, the 
polarizer itself may be colored, or a neutral colored polarizer may be 
combined with a tinted substrate to give the desired color transmission 
property. 
In a second embodiment, internal lens element 56 and pane 16 are selected 
based on the transmission of selective wave lengths of light. For example, 
the internal lens element 56 may embody a film of two layers of tinted 
polarizing films laminated so that the angle between the polarization axis 
of the film is 90 degrees. These color polarizing films absorb only the 
light within a selective range of wave lengths. Pane 14 is, in this 
embodiment, a neutral density polarizing material. In this way, the angle 
between the polarization axis of the neutral polarizer and that of the 
internal lens element 56 determines the color transmission property. 
With a hermetically sealed chamber 12, a further benefit can be derived by 
creating a thermal barrier, by virtue of the thermal insulating properties 
of a suitable gas or fluid introduced into and sealed within the chamber. 
Such fluid-filled, sealed chambers act to limit rapid heat exchange, 
thereby minimizing fogging of the lens when moved from a cold to a warm 
environment, for example. 
In a further embodiment of the invention, chamber 12 is filled with an 
optically transmissive fluid, such as microscopic emersion oil, which has 
a similar index of refraction as the internal lens element 56, rear pane 
14 and front pane 16. Fluid 70 surrounds internal lens element 56 and wets 
the entire internal chamber 12, including the inside surfaces of rear pane 
14 and front pane 16, thereby eliminating or significantly reducing the 
reflective refractive interference from light incident on the surfaces of 
the chamber and internal lens element. For practical purposes, 
introduction of fluid into the chamber creates a single unitary optical 
element because of the matching of the index of refraction of the rear 
pane 14, internal lens element 56 and front pane 16. 
In still a further embodiment, chamber 36 is filled with a dry gas and 
desiccant "getter" which serves to absorb any moisture which may tend to 
form on the inner surfaces of the chamber element or the surfaces of the 
internal lens element, as a result of temperature changes and resultant 
condensation. 
Because the present invention seals the rotatable polarizing element of the 
polarizing assembly and each lens assembly 11 from any source of outside 
contamination (e.g. dust, sweat, rain), cleaning of the lens assembly of 
the present invention is no more complicated than cleaning an ordinary 
pair of eye glasses; i.e., the wearer simply gives an occasional surface 
cleaning to the outside surfaces of panes 14 and 16. Additionally, the 
illustrated seal between the outer, user-operated portions of the 
adjustment mechanism (52, 42) and the internal drive components 44, 60 
associated with the internal lens 56 eliminates contamination and 
subsequent cleaning of the portions most closely associated with the 
internal lens surfaces. 
Alternate adjustment mechanisms for the sealed lens assembly of the present 
invention are illustrated in FIGS. 5-14, and 20-24. 
Referring to FIGS. 5-8, a semi-flexible belt 100 with hook portions 102 is 
suitably secured to notches 104 in each internal lens element 56. Belt 100 
rides in a channel 106 formed in the mating frame elements 6a, 6b as best 
shown in FIG. 5. The point at which belt 100 exits chamber 12 between the 
frame elements 6a, 6b is either formed from or includes a relatively soft, 
sealing material, for example, a suitable rubber, which engages belt 100 
in sealing fashion. In the illustrated embodiment the frame material is 
sufficiently resilient to form a dust and water-resistant seal with belt 
100. 
As belt 100 moves back and forth in the direction of the arrows in FIGS. 5 
and 6, the associated internal lens element 56 is rotated accordingly. 
FIGS. 7 and 8 illustrate a gear mechanism for simultaneously rotating the 
internal lens elements 56 of the two lens assemblies 11. One of the 
internal lens elements 56 provided with internal gearing 108 engaged by 
the teeth of an internal gear 144 which rotates on a shaft 140 sealingly 
inserted through a suitable aperture in a gear-receiving socket 141 formed 
in frame elements 6a, 6b. An external, user-adjustable thumb wheel 142 is 
mounted on the portion of shaft 140 outside chamber 12 to rotate internal 
gear 144 and the internal lens element 56 via gearing 108. Rotation of 
thumb wheel 142 by the user simultaneously rotates both internal lens 
elements 56 connected by belt 100. The sealing of the individual lens 
assemblies 11 can be performed in one of the various manners described 
above. Alternately, the lens assemblies 11, their associated chambers 12, 
and the channel 106 in frame 6 can be sealed as an integral unit as will 
be apparent to those skilled in the art. 
Alternatively, belt 100 may consist of either two separate portions or a 
continuous portion, as shown in FIGS. 20 through 24 
Referring first to FIG. 20, an alternative frame configuration 6, 
consisting of front and rear frame members 6b and 6a, is shown. As 
illustrated, the device includes a first pair of panes 16, each pane 
axially associated with a corresponding internal lens element 56. 
Alternately, and as described in detail elsewhere in this specification, 
the device of FIGS. 20 through 24 may be modified to include a second pair 
of rear panes (not shown); the front 16 and rear panes defining a sealed 
chamber within which is housed one of the lens elements 56. Such a 
modification will be apparent to those of ordinary skill in the art, 
according to the disclosure provided herein. According to the internal 
drive means of this embodiment, belt 100 comprises a continuous, unitary 
element. The belt 100 is preferably constructed from a semi-flexible 
material, such as rubber, thin metal wire, or the like. Rear frame member 
6a, which accommodates internal lens elements 56, includes a recessed 
channel 109 corresponding to a portion of the perimetrical face of each 
internal lens. Channel 109 is continuous between each internal lens 56, 
defined in the nose 5 and bridge portions of the frame element 6a as 
channels 107 and 106, respectively. By means of an outwardly projecting 
post 102 (FIGS. 23 and 24), a portion of belt 100 is securely fixed to 
each internal lens by way of adhesive, frictional engagement, or similar 
methods known to those skilled in the art. One lens element 56 further 
includes a driven gear 108 along a portion of its circumferential edge 
(FIG. 20) Driven gear is actuated by an associated external gear 144, 
which can be operated from without the frame assembly by the wearer. 
Referring now to FIG. 21, the components of the drive gear and belt-drive 
assembly can be seen in greater detail. As depicted, external gear 144 
comprises two opposing circular-shaped walls 146, between which is 
sandwiched the gear element 145. Drive gear 108 and gear 145 are in 
mechanical engagement, as described above. Each wall may include gnurled 
circumferential edges, as shown, in order to facilitate operation of the 
external gear by the wearer. Walls 146 and gear element 145 are coaxial; 
the gear element characterized by a somewhat smaller diameter than the 
opposing walls. This configuration creates a retaining slot between the 
walls of the external gear, so as to prevent unwanted lateral movement of 
the internal lens during operation. Drive gear 144 is pivotally secured 
between mated frame halves 6a, 6b by axles 147 which protrude coaxially 
from either side of the gear (FIGS. 20 and 21.) Each axle rests within an 
associated aperture 112 in each frame half 6a, 6b. 
FIG. 22 illustrates in detail the arrangement of the recessed belt-channel 
in one side of frame member 6a. Channels 109 in each side of frame half 6a 
are in communication via channels 106 and 107 in the respective bridge and 
nose portions of the frame half. The outer circumference of channel 
portion 109 is approximately the same diameter as lens elements 56 (not 
shown). Accordingly, belt 100 (not shown) engages a region of the outer 
perimeter of each lens element 56. It will, of course, be appreciated by 
those of skill in the art that the internal lenses 56 (not shown) may be 
of a larger diameter than the front panes 16 (not shown), such that the 
channel portions are hidden from view in the assembled frames. 
Though not illustrated, it will be appreciated by those skilled in the art 
that the above-mentioned dual-belt drive mechanism functions in much the 
same manner as the disclosed continuous-belt mechanism; comprising 
essentially the same elements as the continuous-belt assembly. According 
to this alternate embodiment, however, belt 100 consists of first and 
second belt portions. Each such portion is characterized by opposing 
terminal ends, with the ends of each belt engaging both internal lenses 
56. Accordingly, the distinct belt portions are spaced, each occupying 
either the nose 107 or bridge 105 channels. (FIG. 20.) 
As depicted in FIGS. 23 and 24, it can be seen that both the dual and 
continuous-belt configurations result in simultaneous lens 56 rotation. 
According to the disclosed gear mechanism, rotation of internal gear 144 
by the wearer affects rotation of the associated lens 56 through movement 
of internal gearing 108. By virtue of the belt connection between each 
lens at posts 102, rotation of one lens result in simultaneous rotation of 
the other lens. This rotation can proceed in either direction (indicated 
by arrows), according to the direction of internal gear 144 rotation. 
A slide-operated embodiment of the belt drive of FIGS. 5-8 is shown in 
FIGS. 9 and 10. Instead of external and internal gearing to rotate one of 
the internal lens elements 56 and the connecting belt 100, the embodiment 
of FIGS. 9 and 10 uses a magnetic follower element fastened to belt 100 in 
channel 106, movable back and forth between the individual lens assemblies 
11. 
An external sliding magnet 242 with a user-operated driver 243 is located 
to slide back and forth immediately above a follower 244 on belt 100. 
Magnet 242 is also attached to drive 243 and slides within a separate 
chamber 208 above channel 106. As slide magnet 242 is moved back and forth 
in the direction of the arrow in FIG. 9, internal follower 244 and belt 
100 are accordingly moved back and forth to simultaneously rotate internal 
lens elements 56. Sealing of the individual lens assemblies can be 
accomplished by sealing follower 244 within sealed frame elements 206a and 
206b. In this embodiment sealing is simplified since there is no need for 
physical connection between driver 243 and follower 244. 
FIG. 25 depicts a further alternate embodiment of the present invention, 
wherein only rotatable internal lens-elements 56 are disposed within the 
mated frame halves 6a and 6b (shown as mated-frame 6). According to this 
configuration, the front panes 16 of the lens assembly are detachably 
superimposed on the internal lens-elements 56 by means of a clip-on frame 
6c. This permits the wearer to selectively alter the superimposed front 
panes 16, according to individual preference. Alternatively, the wearer 
can forego using the superimposed frame 6c altogether. Of course, it will 
be apparent to those skilled in the art that this embodiment of the 
present invention can be modified to function with any of the adjustment 
mechanisms disclosed herein, though it is preferably suited to incorporate 
any of the disclosed belt-drive mechanism. 
FIGS. 26 and 27 illustrate the embodiment of FIG. 25, incorporating an 
alternate means by which frame 6c is detachably secured to frame 6. 
According to this embodiment, frame 6 includes a number of externally 
exposed, recessed grooves 700. Each groove is integral to the body of 
frame 6, and corresponds to one of several protrusions 710 extending from 
frame 6c. Referring to FIG. 27, both protrusion 710 and groove 700 are 
designed to be detachably mated in a snap-fit arrangement. To this end, 
protrusion 710 includes a bulbous tip 711 which fits securely within the 
semi-cylindrical channel defined by groove 700. As illustrated, the upper 
edges 701 of the groove, defined by its opening, includes rounded shoulder 
portions 702 extending the length of each edge of the groove. Each rounded 
edge facilitates the easy insertion of protrusion 710 in groove 700. 
Yet a further embodiment of a belt-type adjustment mechanism for internal 
lens elements 56 is shown in FIGS. 11-12, using separate belt portions 300 
for each lens element, directly driven by a rotatable knob 301 extending 
through suitable aperture 303 in the frame elements 6a, 6b in nose piece 
8. Using central knob 301, lens elements 56 can be simultaneously rotated 
in a manner apparent from the illustration. 
Referring to FIGS. 13 and 14, a combined belt and gear drive mechanism for 
rotating internal lens elements 56 is shown. 
A closed loop belt 400 enters each sealed lens assembly 11 through channels 
406 in the frame members 6a, 6b. An internal drive element 444 comprising 
a pulley wheel and gear is rotatably affixed within frame socket 441 on a 
suitable shaft 440. The pulley wheel portion of internal driven element 
444 engages belt 400, while the gear portion of drive element 444 engages 
gear 108 and internal lens element 56 within the sealed chamber of each 
lens assembly. 
An external drive element 442 comprising a pulley wheel rotating on a shaft 
443 frictionally engages belt 400, such that when external drive element 
442 is rotated, the belt 400 actuates the internal drive elements 444 in 
the sealed lens assemblies to rotate internal lens element 56. 
External drive 442 can be actuated directly, for example by rotating it 
with the thumb and forefinger. 
Sealing of each individual lens assembly and the internal chamber 
containing internal lens element 56 can be accomplished in a manner 
similar to that described in reference to the embodiment of FIGS. 5 and 6. 
For example, channels 406 can be formed from or include a suitable sealing 
material which sealingly engages belt 400 but still allows movement of the 
belt. 
The closed belt drive 400, 442 shown in FIG. 14 also can be used in 
connection with other embodiments of the invention. For example, the FIG. 
14 belt drive could be used in FIG. 4 to drive gears 42 on each assembly 
11. In this case, the diameter of main gear can be arbitrarily chosen. 
Although the above embodiments describe incorporation of the invention into 
spectacles, a still further embodiment can be seen in FIGS. 15-17, in 
which a single sealed lens assembly 11 is provided with an adjustment 
mechanism. The invention can be used as a traditional optical filter, for 
example: as a single face mask type lens; with a camera lens, photographic 
enlarger, a photographic printer or the like; with a telescope lens; etc. 
In the single lens assembly embodiments of FIGS. 15-17, two alternate, 
central adjustment mechanisms for the single internal lens element 56 are 
shown in FIGS. 16 and 17, respectively. In FIG. 16, a simple, central 
internal gear 544 engages gearing 108 on internal lens element 56 to 
rotate it in two directions. Internal gear 544 is rotatably mounted on a 
sealed shaft 540 extending through suitable apertures in a gear-receiving 
socket 541 formed by the mating frame elements 6a, 6b. An external thumb 
wheel 542 (FIG. 15) mounted on the portion of shaft 540 extending from the 
sealed chamber 12 through frame 6 is used to rotate the internal lens 
element 56 as desired. 
In FIG. 17, a mechanism is shown using an external worm gear 544a engaging 
gearing 108 on lens element 56. External worm gear 544a is located in 
socket 541a, and a drive shaft 540a extends from the socket and can be 
rotated by a suitable thumb knob 542a. 
In FIGS. 18-19, another embodiment of a sealed rotatable chamber is shown 
using only two lens elements 614 and 616 joined in sealing fashion and 
rotatable relative to one another. A large o-ring 650 is mounted in a 
groove 606 on the rim of rear pane 616. The frame wall 617 wall of the 
front pane 614 when assembed to rear pane 616 overlies and sealingly 
engages the rim portion of the rear pane 616 and o-ring 650 such that the 
front pane can be rotated with respect to the rear pane. The o-ring 650 
seals the chamber defined by the assembled front pane 614, rear pane 616, 
the wall part 617 of the front pane, and the o-ring seal on the frame or 
rim of the rear pane 616. The front pane 614 and the rear pane 616 are 
both polarizers in this embodiment. 
In the illustrated embodiment, each front pane 614 is individually rotated 
relative to the corresponding rear pane 616 by directly rotating frame 
portions 617 as shown by the arrows. However, various gear, belt and other 
drive mechanisms can be employed to rotate both panes 614 simultaneously, 
for example as described above.