U.S. patent application number 10/050366 was filed with the patent office on 2002-08-15 for optical stack of laminated removable lenses for face shields, windows, and displays.
Invention is credited to Wilson, Bart, Wilson, Seth, Wilson, Stephen S..
Application Number | 20020109922 10/050366 |
Document ID | / |
Family ID | 23783719 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020109922 |
Kind Code |
A1 |
Wilson, Bart ; et
al. |
August 15, 2002 |
Optical stack of laminated removable lenses for face shields,
windows, and displays
Abstract
A stack of laminated transparent lenses consists of two
alternating optically clear materials in intimate contact. The
materials are a plastic lens and clear adhesive. The adhesive is
uninterrupted. The lens and the adhesive have refraction mismatch
of less than 0.2. A tab portion is part of each lens acts as an aid
in peeling way the outermost lens after contamination of the lens
layer during racing conditions. The lens stack can be mounted to
the posts on the face shield or laminated directly to a
windshield.
Inventors: |
Wilson, Bart; (San Juan
Capistrano, CA) ; Wilson, Seth; (San Juan Capistrano,
CA) ; Wilson, Stephen S.; (San Juan Capistrano,
CA) |
Correspondence
Address: |
Kit M. Stetina
STETINA BRUNDA GARRED & BRUCKER
Suite 250
75 Enterprise
Aliso Viejo
CA
92656
US
|
Family ID: |
23783719 |
Appl. No.: |
10/050366 |
Filed: |
January 16, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10050366 |
Jan 16, 2002 |
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09449318 |
Nov 24, 1999 |
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6388813 |
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Current U.S.
Class: |
359/630 ;
351/155 |
Current CPC
Class: |
B32B 27/08 20130101;
B32B 2307/748 20130101; B32B 2419/00 20130101; Y10T 428/1471
20150115; B32B 2307/40 20130101; B60J 1/2094 20130101; G02B 3/0068
20130101; B32B 2457/20 20130101; B32B 2307/412 20130101; G02B 1/11
20130101; B32B 7/06 20130101; B32B 7/12 20130101; B32B 27/36
20130101; A61F 9/025 20130101; B32B 2437/04 20130101; B32B 2255/10
20130101; B32B 2307/732 20130101; B32B 2250/244 20130101; B32B
3/266 20130101; B32B 2037/1276 20130101; B32B 2307/418 20130101;
A42B 3/26 20130101; B32B 2367/00 20130101; Y10T 428/14 20150115;
Y10T 156/10 20150115; G02B 1/18 20150115; B32B 3/02 20130101; B32B
37/12 20130101; B32B 2605/006 20130101 |
Class at
Publication: |
359/630 ;
351/155 |
International
Class: |
G02B 027/14; G02C
003/00 |
Claims
What is claimed is:
1. An optical stack of laminated removable lenses for affixing to a
face shield on a helmet comprising: a plurality of superposed
removable lenses adhesively affixed to one another; each said
removable lens being held to each successive lens with a clear
uninterrupted adhesive layer interposed between each said removable
lenses; each said lens having a removal tab portion on at least one
end which does not have any adhesive layer on either side of said
tab portion for allowing the wearer of the helmet to quickly grasp
said removal tab portion for removing the top lens and exposing a
at clean lens directly underneath said removed top lens.
2. The optical stack of removable lenses as recited in claim 1
further comprising: a second removable tab portion opposite the end
of said removal tab portion.
3. The stack of removable lenses as recited in claim 1 further
comprising: slots for mounting said optical stack of removable
lenses to a face shield.
4. The stack of removable lenses as recited in claim 1 further
comprising: means for mounting said optical stack of removable
lenses to a face shield.
5. The optical stack of removable lenses as recited in claim 1
wherein: said removable lenses and said clear adhesive layers have
an index of refraction between 1.40 and 1.52.
6. An optical stack of removable lenses for affixing to an optical
window comprising: a plurality of generally rectangular superposed
removable lenses adhesively affixed to one another and forming a
continuous perimeter; each said removable lens being held to each
successive lens with a clear uninterrupted adhesive layer
interposed between each said removable lens; said perimeter having
a generally straight edge portion; the area adjacent said straight
edge portion having a banded portion that does not have any
adhesive affixed to any of the layers of film to assist in allowing
each said film layer to be peeled off successively along said
straight edge portion; and a plurality of staggered tabs affixed to
each said film layer and extending from said straight edge portion
to assist the user in removing said uppermost soiled film layer,
and successively removing each said next clean layer as said top
exposed layer becomes contaminated.
7. The stack of removable lenses as recited in claim 6 wherein: the
adhesive layer is foreshortened as to expose a portion of the lens
layers without optical wetting, creating a grasping tab.
8. The stack of removable lenses as recited in claim 6 wherein: an
optically clear adhesive is the last layer to aid in mounting to a
face shield.
9. The stack of removable lenses as recited in claim 6 wherein: the
optical window to which said stack of removable lenses is mounted
includes a windshield, window, face shield, or a video display.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] None
BACKGROUND OF THE INVENTION
[0003] The present invention pertains to the following areas of
technology: Apparel--Guards and Protectors; for wearer's head and
face; eye shields such as goggles having a lens-cover plate; and
windshield covers.
[0004] Face shields are employed in environments where
contamination of the eyes may occur. It is well known in the art
that flexible transparent lenses affixed by numerous methods are
overlaid on the face shield for protection. The lenses are easily
removed and discarded when visibility is reduced from the
accumulation of dirt or other contaminants. In motor sports for
instance, multiple layers of transparent lenses are overlaid on the
face shield, each being sequentially removed as they become
contaminated, because they reduce the visibility of the operator.
The drawback of the lenses in the prior art is that each
transparent lens applied over the face shield is itself a hindrance
to good visibility due to its optical index of refraction. Most
common materials used as plastics have optical indexes of
refraction ranging from 1.47 to 1.498. The index mismatch between
the removable lens and air (air has an optical index of 1.00)
causes a reflection of 4% of the light that would normally come to
the operator's eyes. This reflection effect is additive for each
additional surface to air interface. Then for each removable lens
having two surfaces, the reflections are 8%. Thus a stack of seven
lenses would reflect 42% of the light away from the operator
thereby reducing the brightness of the objects viewed. A second
optical phenomenon occurs simultaneously that also reduces
visibility. The reflections are bi-directional and thus make the
lens stack appear as a semi-permeable mirror to the operator. This
mirror effect further reduces visibility, because the light that
passes through the lens stack reflects off of the operator's face
and then reflects off of the lens stack into the operator's eyes.
The effect to the operator is that he sees his own image on the
inside of the stack nearly as brightly as the objects viewed on the
outside. This significantly reduces visibility.
[0005] Another drawback to this stacking arrangement is that
moisture exhaled by the operator's breath can cloud or fog-up the
lenses also reducing visibility. The air spaces between each lens
allows the moisture to enter this area.
BRIEF SUMMARY OF THE INVENTION
[0006] An object of the present invention is to provide a series of
easily removable optically clear lens stacks that do not cause
reflection to the operator's eyes. The prior art discloses
reflective lens stacks that do cause reflections to the operator's
eyes. An example of this type of prior art of reflective lens stack
is disclosed in U.S. Pat. No. 5,592,698 issued on Jan. 14, 1997 to
Woods.
[0007] Refraction is the change in the direction in which waves
travel when they pass from one kind of matter to another. Waves are
refracted (bent) when they pass at an angle from one medium into
another in which the velocity of light is different. The amount
that a ray of a certain wavelength bends in passing from one medium
to another is indicated by the index of refraction between the two
mediums for that wavelength. The index of refraction indicates the
amount that a light ray bends as it passes out of one substance and
into another. When light passes from air to a denser substance,
such as Mylar film, it slows down. If the light ray enters the
Mylar film at any angle except a right angle, the slowing down
causes the light ray to bend at the point of entry. This bending is
called refraction. The ratio of the speed of light in air to its
speed in the Mylar film is the Mylar film's index of
refraction.
[0008] The present invention includes a series of alternating
optically clear films whose indexes of refraction are matched to
within 0.2 and which will nearly eliminate all reflections to the
operator's eyes. The layers of film are adhesively laminated to one
another and are compliant so there is no air between the layers.
The film layers can be large and generally rectangular in shape
with a tab extending from each of the film layers. The tabs can be
staggered so that the user can remove the top most layer and then
the next succeeding layer. This embodiment of the present invention
can be applied to race car windshields, windows, visors or direct
view displays such as ATM machines that are subject to
contaminating environments. Accordingly, the present invention is
an adhesively laminated multi-layered clear film adapted to be used
on a racer's face shield, or on the windshield of a race car to
keep the viewing area clean during the course of a race.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of an off-road wearer's helmet
showing one embodiment of the present invention affixed to the face
shield of the helmet.
[0010] FIG. 2 is a front elevational view of the helmet shown in
FIG. 1 showing the tab portion without any adhesive for allowing
the wearer of the helmet to easily grasp the tab and peel-off the
soiled top layer of the present invention.
[0011] FIG. 3 is a partial sectional view taken along line 3-3 in
FIG. 2. This view shows the tension post extending outwardly from
the face shield with the left-side end tab portion of the present
invention.
[0012] FIG. 4 is a front elevational view illustrating the present
invention before it is affixed to the face shield of the
helmet.
[0013] FIG. 5 is a top view of the stackable lenses illustrating
seven layers of lens held together by an adhesive applied between
each lens with the thickness of the layers of each lens and applied
adhesive highly exaggerated to clearly show the relationship
between the lenses and the adhesive and also to show the end
portions that do not have any adhesive between each lens layer for
forming the removable tab portions at both ends of the present
invention.
[0014] FIG. 6 illustrates a 60" wide roll of film, which will be
used to cut out the optical stacks that are illustrated in FIG. 4.
The gray stripes illustrate the clear adhesive, and the clear
stripes illustrate the clear film without adhesive. It is to be
understood that the gray stripes are for illustration purposes
only, because the adhesive is clear.
[0015] FIG. 7 is an exploded perspective view illustrating seven
sheets of film layer and seven layers of clear adhesive interposed
between each sheet of film layer. This embodiment is used for
windshields, windows and the like.
[0016] FIG. 8 is a view of the laminated sheets illustrated in FIG.
7 having a rectangular shape with a series of six tabs for removing
each top layer of the lenses successively as the uppermost exposed
lens layer becomes soiled or otherwise contaminated.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention will now be discussed in detail. As
stated above, FIG. 4 is a front elevational view illustrating the
present invention 10 before it is affixed to the face shield of the
helmet. The top view in FIG. 5 illustrates 7 layers of lenses 15
adhesively affixed to each successive lenses. The adhesive layer is
numbered 20. The material used to form the lenses is preferably a
clear polyester. The lens layers are fabricated from sheets of
plastic film sold under the registered trademark Mylar owned by the
DuPont Company. The several trademark registrations for the mark
Mylar list several types of products sold under that mark, and
include polyester film. The type of Mylar used in the present
invention is made from the clear polymer polyethylene terephalate,
commonly referred to as PET, which is the most important polyester.
PET is thermoplastic--that is, it softens and melts at high
temperatures. Uses of PET film include magnetic tapes and shrink
wrap. The adhesive 20 used to laminate the lenses together
sequentially is a clear optical low tack material. The thickness of
each lens will range from 0.5 mil to 7 mil (1 mil is 0.001"). The
preferred thickness will be 2 mil. Even after the adhesive material
is applied to a 2 mil thickness lens, the thickness of the 2 mil
thickness lenses will still be 2 mil. The adhesive has nominal
thickness. As illustrated in FIG. 5, after the seven layers of film
and the six layers of adhesive are laminated together, the overall
thickness of the end product is 15 mils. The term "wetting" can be
used to describe the relationship between the laminated film
layers. When viewing through the laminated layers, it appears to be
one single piece of plastic film. No reflections are evident. The
end tab portions without the adhesive exhibit reflections are not a
hindrance to the user, because these end portions are folded back
over the posts as illustrated in FIG. 3, and do not affect the
visibility of the user.
[0018] The adhesive material 20 will be a water-based acrylic
optically clear adhesive or an oil based clear adhesive, with the
water based adhesive being the preferred embodiment. After the
seven layers are laminated or otherwise bonded together with the
adhesive layers, the thickness of each adhesive layer is negligible
even though the adhesive layers are illustrated in FIGS. 4 and 5 as
distinct layers. FIG. 5 is a top view of the stackable lenses
illustrating seven layers of lens held together by an adhesive
applied between each lens with the thicknesses of the layers of
lenses and applied adhesive highly exaggerated to clearly show the
relationship between the lenses and the adhesive and also to show
the end portions that do not have any adhesive between each lens
layer for forming the removable tab portions 25 at both ends of the
present invention.
[0019] The individual stackable lenses package, illustrated in FIG.
5 for use with racing helmets, can be fabricated from a roll of
film as illustrated in FIG. 6. The film in FIG. 6 includes seven
layers of clear polyester film, and having the water-based acrylic
adhesive laminating the seven film layers to one another. Keep in
mind that each layer of the lenses can be easily peeled away as the
top layer exposing the next clean lens. Each succeeding lens layer
can be removed as the top lens becomes contaminated with dirt and
grime during racing conditions.
[0020] Referring back now to FIG. 3. As previously stated, FIG. 3
illustrates the tension post 60 extending outwardly from the face
shield 55 with the left side end tab portion 25 of the present
invention illustrated. The face shield 55 has a left tension post
60 and a right tension post 65. The present invention 10 has the
following dimensions: 18" in length; 21/2" in height; and about 15
mils in thickness (1 mil is 0.001"). The present invention is
symmetrical about it vertical medial axis and about its horizontal
medial axis. The left end has a removable tab portion 25, and the
right end has a removable tab portion 35. The area 15 indicates
where the adhesive 20 is applied to the layers of the lens 15. The
bilateral demarcation lines 31 and 41 indicate where the adhesive
stops on either side. The demarcation lines 31 and 41 also indicate
where the tab portions begin. The present invention has a pair of
bilateral keyhole-shaped slots 27 and 37 for demountably engaging
the two helmet posts 60 and 65 respectively. The curved distance
between the two helmet posts 60 and 65 is the same as the distance
between the centers of the pair of slots 27 and 37. The user
secures the lenses to the face shield by positioning the slots
adjacent the helmet posts and passing the posts through the slots.
It is preferable that the remainder of the tab portion outboard
from the slot be folded back upon itself so that the finger hole is
also passed through the helmet post. This is illustrated in FIG. 3.
The proper installation of the present invention on the helmet
requires the user to position the bottom lens of the stack through
the post hole by passing the post through the slot, then folding
back the remainder of the tab portion 25 so that post passes
through the finger hole 29. This is done for each lens working from
the bottom up until the tab portion 25 of the top lens extends
unfolded as illustrated in FIG. 2. In this manner, the helmet
wearer can easily put his index finger through the finger hole
topmost lens layer. The clean layer below the removed layer is then
exposed and the removal tab portion on the exposed layer will
spring back to the unfolded position to expose the finger hole so
that the helmet wearer can easily remove that layer after it
becomes soiled and contaminated. The plastic material forming the
lenses is resilient and will spring back to its unfolded position
and extend outwardly from the face shield. The thicknesses of the
layered lenses and folded tab portions illustrated in FIG. 3 are
highly exaggerated to clearly show the folding relationship. In
actual practice seven lenses and seven tab portions with be stacked
into the space between the end of the post and the outer surface of
the face shield. Remember that there is no adhesive between the tab
portions. This allows the removal tab portions to fan out. They do
not stick to one another.
[0021] The present invention as shown in Drawing Figures has
removal tab portions at both ends. This allows a right or
left-handed person to easily remove the topmost layer. It also
allows the driver to pull the tab with either hand depending on the
circumstances of the race. It is to be understood that the present
invention includes a laminated lenses with only a left tab portion
25, or only a right tab portion 35, or both a left and a right tab
portion.
[0022] The windshield embodiment 100 illustrated in FIGS. 7 and 8
will now be discussed in detail. An optical stack of removable
lenses for affixing to an optical window such as a racing car
windshield is disclosed in FIG. 8. The embodiment 100 has a
plurality of seven generally rectangular superposed removable
lenses 105 adhesively affixed to one another. The outer perimeter
is continuous. Each of the removable lens 105 is held to each
successive lens with a clear uninterrupted adhesive layer 110
interposed between each of the removable lens. The perimeter has at
least one generally straight edge portion 115. In the embodiment
illustrated in FIG. 8, the perimeter is rectangular and has four
straight edge portions, one for each side. It is to be understood
that the invention could be practiced with only one generally
straight edge portion. The area adjacent to the straight edge
portion 115 has a banded portion 120 that does not have any
adhesive affixed to any of the layers of film to assist in allowing
each said film layer 105 to be peeled off successively along the
straight edge portion. A plurality of staggered tabs 125 are
affixed to the film layers one-at-a-time. The tabs 125 extend from
the straight edge portions 120 to assist the user in removing the
uppermost soiled and grimy film layer, and to successively remove
each next clean layer as the top exposed layer becomes
contaminated.
[0023] The adhesive layer can be foreshortened so as to expose
successively a portion of the lens layers without optical wetting
to create a grasping tab.
[0024] The stack of removable lenses as illustrated in FIGS. 7 and
8 can have an optically clear adhesive as the bottom last layer to
aid in mounting the stack of lenses to the windshield. The stack is
affixed to the windshield in much the same way that tinted window
plastic film is affixed to a window. The windshield is sprayed with
water and the bottom adhesive layer with the stack is then applied
to the windshield. Air bubbles and the like are eliminated with a
squeegee appliance. The bottom layer becomes "wetted" to the
windshield.
[0025] The stack of removable lenses 100 can be applied to any type
of optical window such as windshield, window, face shield, or a
video display. It is common at an ATM terminal to have a video
display for the customer. The surface of the display can be kept
clear by using the present invention. Herein in what is conceived
to be the best mode contemplated, it is recognized that departures
may be made therefrom within the scope of the invention which is
therefore not to be limited to the details disclosed herein, but is
to be afforded the full scope of the invention.
* * * * *