Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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DESCRIPTION
APPARATUS FOR ENHANCING VISUAL PERCEPTION OF
SELECTED OBJECTS IN RECREATIONAL AND SPORTING
ACTIVITIES
TECHNICAL FIELD
The invention relates generally to optics for sports-related activities.
The adage "keep your eyes on the ball" is a familiar refrain to those who
participate in sports. Success in these activities requires a participant to
be
able to accurately perceive a moving object. Practice is the traditional
approach to improving the ability to keep ones eye on the ball. But practice
requires time and patience. Most people do not have the time or inclination
to practice or talent to be overcome their natural limitations. Even well-
seasoned professionals in some sports may have trouble perceiving a moving
object, especially where the skills of the participants have pushed the sport
to
the point where the speed of the object exceeds the natural ability of the
players to accurately perceive it. In sports, particularly in those where a
fast
moving object must be followed, a participant's further development in the
sport may be slowed, and fans, referees, coaches, and other observers of the
sport will have more difficulty following the activity.
BACKGROUND ART
The invention enhances visual perception of an object used within the
activities with respect to its background. The invention may be used during
practice, playing and watching of the activities, and requires no special
training. The invention enhances the ability of participants to visually
perceive a selected object, such as a ball, and thus offers the opportunity to
improve their performance.
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DISCLOSURE OF THE INVENTION
According to the invention, a specially adapted optical filter is
provided to a participant or observer of the activity and supported in a
location between the observer's eyes and an activity that visually enhances a
selected object used in such activities with respect to the background of the
object. The selected object is provided with a surface that reflects or emits
light predominantly within one or more comparatively narrow predetermined
ranges of wavelengths within the visible spectrum. The optical filter is
selected to pass more incident light at wavelengths overlapping the
wavelengths at which light either reflected, emitted or both from the object
peaks in intensity. To the observer or participant, the vision of moving
object is thus enhanced with respect to the background.
In accordance with a further aspect of the invention, eye wear for a
participant or observer includes a lens (corrective or non-corrective) or
other
substantially clear, solid element that is treated with a dye or a mufti-layer
optical interference coating which tends to pass light in a range of the
visible
spectrum with one extreme of this range proximal to and including the
spectrum corresponding to the predominant color characteristic of the object.
In one preferred embodiment, a blue dye is applied to a transparent lens for
enhancing viewing of an optical yellow tennis ball.
The invention is adaptable to other activities. These activities may
include, for example, racquetball, squash, golf, baseball and other activities
which require a moving or stationary object be contacted by the hand of an
object held by the hand of a player. Additionally, the invention is useful for
improving safety in activities such as water skiing, hunting and military
training maneuvers by providing to participants clothing or other wearable
objects having distinctive and predominant color characteristics and to
observers eye wear of enhancing perception of such clothing or objects.
These and other aspects and advantages of the invention will be
apparent in the following description of the appended drawings illustrating a
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preferred embodiment of the invention.
Figure 1 is a graph showing relative reflectance of visible light from
a standard, fluorescent yellow tennis ball as a function of wavelength.
Figure 2 is a graph showing relative intensity of florescence at visible
wavelengths from a standard, fluorescent yellow tennis ball as a function of
wavelength.
Figure 3 is a graph of percent transmittance versus wavelength of a
typical prior art sunglass lens specially treated for attenuation of ultra-
violet
Light.
Figure 4 is a graph showing percent transmittance at visible
wavelengths of an optical filter applied to a lens in accordance with a
preferred embodiment of the invention for enhancing viewing of an optical
yellow tennis ball.
Figure 5 is a graph showing percent transmittance at visible
wavelengths through a second a lens having a second optical filter in
accordance with the invention.
Figure 6 illustrates standard eye wear incorporating a lens having an
optical filter in accordance with the invention.
Figure 7 is a schematic representation of a viewing stand and activity
having a specially translucent surface between an observer of an activity and
the area of activity that supports an optical filter for enhancing viewing of
an
object having a predominant color characteristic.
BEST MODE FOR CARRYING OUT THE INVENTION
In the following description, like numbers refer to like parts.
Referring to Figure 1, curve 100 illustrate relative reflectance of
electromagnetic radiation within the visible spectrum from a typical
fluorescent yellow tennis ball. There is a peak 102 of radiation in the green-
yellow area of the visible spectrum centered approximately around 500 to
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525 Nanometers. A "peak", as referred to herein, is a local maximum of
intensity flanked on each side of the peak by a local minimum of intensity
that is substantially less than the peak intensity. The relative reflectance
rolls off sharply on each side of this peak. Toward the blue side of the peak,
the relative reflectance falls to near zero at approximately 450 Nanometers.
However, on the red side of the peak, the reflectance curve decreases less
rapidly to a substantially lower level in the range of 600 Nanometers. As
used herein, the bandwidth of a peak of intensity of incident radiation or
light is the range of wavelengths between half power points on the intensity
curve on either side of the peak. However, if the intensity on a side of the
peak does not decrease to a level below the half power point, then the edge
of the bandwidth on that side of the peak is the 50 % point between the peak
and the local minima.
Referring now to Figure 2, in addition to reflecting visible light, the
optical yellow coating on the tennis ball also emits light in the visible
range
through florescence. Graph 200 indicates that the florescence of a typical
fluorescent yellow tennis ball has a pronounced peak 202 at around 500 to
525 Nanometers that rolls off sharply on each side. The bandwidth of peak
202 substantially correlates with or overlaps the bandwidth of peak 102
(Figure 1) for reflectance.
Referring now to Figure 3, curve 300 illustrates a typical
transmission characteristic for a sunglass lens treated with an optical
coating
on the surface of the lens that attenuates ultraviolet light. As indicated by
curve 300, the tranrltisttance (measured by the percentage of incident light
transmitted through the lens) of the sunglass lens remains substantially
consistent over the visible range, though it may have a tint due to imbalance
in one region of the spectrum with respect to other regions. It does not,
however, have pronounced peaks in any particular range.
Referring now to Figures 1, 2, and 4, curve 400 is a graph that
illustrates the percent of incident light as a function of wavelength
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transmitted by a lens having an optical filter according to the present
invention. As used herein, "lens" refers to conventional eyeglass lenses that
correct and those that do not correct vision, and to solid, substantially
transparent material, without any limitation to shape or size, that may
5 support an optical filter interposed between an eye and an object to be
viewed and through which the object is to be viewed. The transmittance of
the lens has a pronounced peak of transmittance 402 that is centered
substantially around 500 to 525 Nanometers. On each side of the peak is a
wave length at which transmittance is fifty percent of the peak transmittance.
The range of wavelengths between these two fifty percent of peak
transmittance points will be referred to herein as the bandwidth of the peak.
The bandwidth of the peak transmittance 402 correlates with and/or partially
overlaps the bandwidth of the peaks 102 and 202 of light reflected and
fluoresced by the optical yellow tennis ball shows in Figures 1 and 2 and the
peaks of curves 102 and 202 are located substantially within the bandpass of
curve 400 and proximal to one edge of the bandpass of curve 400. It is
preferred that the bandwidths of the peaks 102 and 202 of reflectance and
fluorescence of the tennis ball lie within the filter spectrum and proximate
either the upper or lower edge of the filter spectrum whereby the ball is
perceived by the user as having its true color, and the background is tinted
with a different color adjacent in the spectrum. The transmittance of the lens
rolls-off rather sharply on each side of its peak 402, approaching zero toward
the limits of the visible spectrum in each direction. Thus, the lens will tend
to enhance perception of the tennis ball against a background that reflects or
emits light relatively uniformly across the visual spectrum or predominantly
in parts of the visual spectrum outside the peaks of reflectance 102 and
florescence 202 of the tennis ball.
In tennis, as in most other activities, it is desirable to view at least
some of the background. Therefore, the remainder of the visible spectrum,
outside the peak 402 is not completely attenuated. Furthermore, as tennis is
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often played out-of doors, in the intense sunlight, the lens attenuates to a
less
degree light within the peak range to protect the yes of the participant or
observer from the sun.
To further enhance perception of the tennis ball, the transmittance of
lens, as seen in curve 400, rolls off significantly more rapidly on the red
side
of the curve than on the blue side of the curve and falls to near zero on the
red side. Transmittance in the blue region remains greater than zero and
therefore the background viewed through this filter has, in general, a bluish
tint. As can be seen by portion 104 of curve 100, a yellow tennis ball
actually reflects a significant amount of red colored light, though not with
quite the intensity of light within the green-yellow region of spectrum.
Reducing the transmittance in the red region of the spectrum tends to
emphasize the predominant yellow-green color of the ball while removing
orange and lower wavelengths associated primarily with the background,
thus further enhancing perception of the tennis ball while maintaining
sufficient transmittance of other parts of the visible spectrum to reasonably
view the background.
One example of a suitable optical filter is a thin film, poiycarbonate
filter, manufactured and distributed under the name Lee Filters by Lee
Panavision International, Inc. of Andover, Hampshire, England, and
designated "Peacock Blue", No. HT-115. This filter fairly approximates the
desired transmittance shown in Fig. 4 when applied to a neutral,
substantially transparent solid support element such as a glass lens and thus
provides a desired enhancement of the perception of an optical yellow tennis
ball against a typical background encountered when playing tennis.
Referring now to Figures 1, 2, and 5, in another embodiment of the
invention, a second transmittance for an optical filter carried by a lens is
illustrated by curve 500. It has a peak 502 which is substantially correlated
to peak 102 in the reflectance of the tennis bail and to peak 202 in the
florescence of the tennis ball. Unlike the transmittance curve 400 illustrated
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in Figure 4, the transmittance curve 502 significantly roll-offs on each side
of the peak to substantially level plateaus 504. The transmittance of the lens
thus emphasizes the predominate yellow-green appearance of the ball while
allowing a substantial amount of the remainder of the visible spectrum to be
transmitted. The tennis ball is enhanced without significantly attenuating
light reflected and emitted by the background.
Referring to Figure 6, eyeglasses 600 include two lenses 602
supported mounted to frame 604 to support the lens within the field of vision
of a person wearing the frame. Eyeglasses are well-suited for supporting a
lens in font of eyes of a participant who must move during the activity, such
as a player in a tennis game. The specific design of the frame and the shape
and size of the lenses is a matter of preference of the wearer. Each lens 602
is comprised of clear, neutral glass. A layer of thin plastic film is bonded
to
one surface of the glass lens. The thin, plastic film is impregnated with a
dye that has a transmittance substantially as illustrated in Figures 4 or 5.
Alternately, the dye may also be mixed in with a plastic substrate and
molded into a rigid plastic lens. Other types of optical filters may be
applied
to the surface of the glass. One type of well known optical filter is an
optical
interference coating containing several layers of anti-reflective material
deposited on the surface of the glass lens. The constitution and thickness of
the layers are chosen to refract and to reflect predetermined wavelengths of
light in a predetermined manner to create predetermined patterns of
constructive and destructive interference.
Alternately, instead of a pair of eye glasses, other forms of eyewear,
for example goggles or contact lens, could be treated in a similar fashion
with a dye or interference coating to give the desired transmission
characteristic that enhances an object having a predetermined predominant
color characteristic with regard to the background, as exemplified by Figures
4and5.
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Referring now to Figure 7, viewing stand 700 is located adjacent to
court 702 on which player 704 is playing tennis with tennis ball 706. The
stand includes a sheet of substantially transparent material, such as a plate
of
glass or plastic, supported between view 708 and court 702. Included with
transparent material is an optical filter having the transmittance
characteristic
illustrated by the graphs of Figure 4 or 5. Observers seated in the stand thus
have an enhanced view of the tennis ball. The viewing stand is adaptable for
viewing other types of playing areas and the substantially transparent
material adaptable to include an optical filter having a transmittance
characteristics that enhances viewing of an object in the playing area having
a predominant color by attenuating or reflecting colors in the visible
spectrum outside of the predominant color.
The foregoing description is of preferred embodiments of the
invention only and intended only as examples, not limitations, of the
invention. The scope of the invention is set out in the appended claims.
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