Note: Descriptions are shown in the official language in which they were submitted.
CA 02280420 1999-08-12
Patent Application
of
W. Steve G. Mann
for
SELECTIVE VITRIONIC VIEWING CONCEALED BY MATERIAL
SUCH AS POLYMER DIFFUSER
of which the following is a specification:
FIELD OF THE INVENTION
The present invention pertains generally to providing an optically
nonscattering view
through apparently opactue noaterials.
BACKGROUND OF THE INVENTION
Increasingly, optical instrumentation is concealed behind dark glass, or
mirrored
glass. When the optical instrumentation is the human eye, it is often
concealed
behind partially silvered mirrors, such as so-called two-way or one-way
mirrors so
that people cannot easily see the optical instrumentation (e.g. when the
optical
instrument is another human observer hidden behind the partially silvered
mirrors or
the like) or so that people cannot determine whether or not they are being
watched
(e.g. whether or not said optical instrumentation is present).
For purposes of crime deterrence, mirrored plexiglass sheets a,re often
inserted
in place of at least some of the ceiling tiles in an establishment where crime
might
otherwise be present. These may contain optical instruments such as video
cameras,
whereas patrons in the establislrrzrent cannot easily see where these video
cameras are.
aimed, or behind which ceiling tiles these cameras are located.
Optical instruments may be concealed behind dark transparent materials. Hemi-
spherical domes are often used for this purpose. Optical instruments are often
con-
cealed behind dark signage, such as an "EXIT" sign surrounded by what appears
like
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CA 02280420 1999-08-12
black plexiglass, but what is actually dark smoked pleaiglass for concealment
of a.
video camera..
Optical instruments that operate in the infrared, such a.s the presence
detectors
inside elevator doors that prevent the doors from closing when a person is
standing
between them, are often concealed behind a material that looks like black
plastic
in the visible region of the spectrum, but is transparent in the infrared.
Therefore.,
unsightly wiring, and long circuit boards upon which unsightly integrated
circuits
and perhaps forty to fifty infrared light emitting diodes (LEDs) or detectors
(LEDs
in one door and detectors on the other), are invisible to people entering the
elevator.
Because the material is transparent in the infrared, the elevator can "see" if
someone
is standing between the doors. In this wary the doors can be programmed to not
close
until the person has entered or left the elevator car.
Other devices such as water closets, urinals, lavatories, showerbaths, hand
dryers,
soap dispensers, etc., often incorporate a device having a viewing window that
is made
of what appears to be black glass or plastic, but what is actually either
darkly smoked
transparent material, or is transparent in the infrared and dark (e.g.
absorbing) in
the visible. Optical instruments in these devices determine. when a. user is
present.
For example, water closets and urinals may flush automatically when a user has
been
present for a predetermined time period and then subsequently departs.
Lavatories,
soap dispensers, and hand dryers may be designed to operate when hands are
placed
under the faucet of the lavatory, the spout of the soap dispenser, or the air
opening
of the hand dryer. Showers may be designed to switch on when a person is
present
under the nozzle of the showerbath. Some showerbaths can be designed so that
they
will only switch on when the person is unclothed (e.g. so that persons walking
past
but not intending to shower do not accidentally get wet).
These devices could also operate proportionally, e.g. to control a. showerbath
so
it gradually increases the flow of water as the user gets closer, so that the
user would
not be surprised by a. sudden deluge of water, and so that the user could
"test the
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CA 02280420 1999-08-12
water" gradually in order to have an increased confidence in what might
otherwise
be a. startling or uncertain technology.
One drawback of these devices is vandalism, such as destruction of the viewing
windows by people who do not like the idea, of being under surveillance by
these
machines. Viewing windows in restroom facilities and the like are often found
in a
scratched or otherwise damaged state.
Diffuse viewing windows are often used for systems such as infrared motion de-
tectors in which a clear optical image is not required. These, however, often
lac.lc
the precision to determine the range of (distance to) a person standing in
front of a
fixture, or the like.
The infrared nnotion detectors having a frosty white cover a,re used for
burglar
alarms to detect the overall motion in a. room, but lack the degree of
precision to
detect the presence of an object in a particular location without being
falsely triggered
by motion elsewhere in a room, or they lack the precision to determine how far
away
the object is. For example, water closets a,re typically located in stalls or
cubicles in
which, a door swings inward within close to where the bowl of the water closet
ends.
Ordinarily, a person seated on the water closet is much closer to the
instrument
than the door would ever get. However, in a. men's restroom, it is common that
a
person might be standing to urinate into the bowl, rather than sitting. In
this case the
person might be a few centimeters from where the bowl ends, such that there.
is very
little difference in range from where the person is standing and where the
door may
swing inwards. The ability to discriminate such a small difference in range is
typically
beyond the capability of instruments located behind a diffuse viewing window.
SUMMARY OF THE INVENTION
Accordingly, the present invention in one aspect comprises a. surface having a
smooth white appearance, behind which optical instruments can be concealed.
According to another aspect of the invention, there is provided a square white
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CA 02280420 1999-08-12
tile, having the appearance of an ordinary bathroom tile, bttt containing
optical iu-
strumentation incorporated into the tile.
According to another aspect of the invention, there is provided a vitreous
white
china fixture incorporating optical instrumentation concealed therein.
According to another aspect of the invention, there is provided a window, such
as might be used in a dwelling. having a frosty appearance to people outside
the
dwelling, but through which a person may look while wearing special eyeglasses
or
special contact lenses, such that the person can see out of the window, even
after°
dark, but neighbours cannot easily see in, even if the person has left his or
her lights
turned on in the room.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail, by way of examples which
in no way are meant to limit; the scope of the invention, but, rather, these
examples
will serve to illustrate the invention with reference to the accompanying
drawings, in
which:
FIG. 1 illustrates the use of the temporally selective view diffuser with
optical
instrumentation measuring distance (range) to a user of a toothless
showerbath.
FIG. 2 illustrates the timing wa,veforms of the toothless showerbath.
FIG. 3 shows the optical instrumentation built dire<;tly into the vitreous
china of
a sanitary fixture.
FIG. 4 illustrates how the temporally selective view diffuser can be used on
the
window of a dwelling so that neighbours cannot see into the window even late
at night
when the lights are left on inside the room, yet occupants can still se out.
FIG. 5 shows the timing diagram of the window including the waveforms showing
the encrypted timing, rather than the simple periodic tinning that was used in
FIG. '?.
FIG. 6 shows the block diagram of the window control system.
FIG. ? shows an embodiment of the viewing apparatus built into a, contact
lens.
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CA 02280420 1999-08-12
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention shall now be described, in detail, with reference to the
pre-
ferred embodiments shown in the drawings, it should be. understood that the
descrip-
tion is not to limit the invention only to the particular embodiments shown
but rather
to cover a,ll alterations, modifications and equivalent arrangements possible.
within the
scope of the appended claims.
When it is said that object ''A" is "borne" by object "B", this shall include
the
possibilities that A is attached to B, that A is bonded onto the surface of B,
that A
is imbedded inside B, that A is part of B, that A is built into B, or that A
is B.
FIG. 1 is a diagram depicting a, person 110 using a showerbath control system
in
which an imager 120 is responsive to rays of light 121 from user 110. A
satisfactory
imaging system is a commercially available video camera. Specific optical
rangefinders
may also be used. One or more phototransistors or photodiodes could be
arranged to
provide a measure of distance to user 110. A linear array of light sensors
could also be
used. However, owing to mass production, a two dimensional array of light
sensors
may actually cost less than a. one dimensional array (e.g. complete video
cameras
cost less than X10, whereas specialized optics can often cost more).
The output signal 1'2'2 from imager 120 may be the output of a specialized
optical
instrument, in the forru of one or more wires, fiber optic, or the like, or
simply a.
standard RS-170 signal on a 7.5 ohm coaxial cable. Signal 122 is supplied to
processor
130 which digitizes signal 122 and applies a simple image processing algorithm
to
estimate at least one attribute (such a.s ra.nge, e.g. distance between user
110 and the
apparatus).
Processor 130 also generates a. waveform 140 of short pulses that a,re high
during
the time to which imager 120 is responsive to light, and low during the time
to which
imager 120 is not responsive to light. Wa,veform 140 switches on high voltage
sources
1,50, rendering tiles 170 optically transparent during the. time which imager
120 is
responsive to light. During the time to which images 120 is not responsive to
light,
6
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high voltage sources 150 are off, causing tiles 170 to diffusely scatter
light.
A satisfactory material for the construction of tiles 170 is Polymer Dispersed
Liquid Crystal (PDLC), or Polymer Stabilized Liquid Crystal (PSLC). Other elec-
trochromic materials may also be used in the construction of tiles 170.
Materials that are glassy, or ceramic, or plastic-like, e.g. smooth hard
materials, that have a degree of scattering or transparency that can be
electrically controlled, will be referred to as vitrionic materials.
PDLC is a very low cost material available from various manufacturers, such as
ALCOM. In commercial applications, in sheet form, PDLC often costs $100 or
less
per square meter, such that the cost of manufacturing one standard four inch
by four
inch bathroom tile made of this material might be expected to be less than one
dollar,
in sufficient quantity.
The showerbath control system depicted in FIG 1 may also incorporate one or
more
light sources 160, also responsive to waveform 140, such that a structured
illumination
approach to imaging user 110 may be used. Preferably light source 160 is an
infrared
laser diode line source providing a fan-shaped beam 161. In this case,
processor 130
calculates the first moment of every row of the image provided by imager 120
and
applies robust statistics to combining the estimates. Typically the image is
digitized
at 480 pixels down by 640 pixels across. The estimate of first moment will be
a floating
point quantity (e.g. subpixel accuracy) and there will thus be 480 such
estimates.
These estimates are combined robustly to provide a single estimate.
An estimate of range is then formulated from a lookup table in processor 130,
and
applied to a showerbath timing algorithm. When user 110 approaches the
apparatus,
the duty cycle of an output valve control signal 179 is varied from zero to
some small
quantity as the user approaches. A fine mist from spray head 171 results. As
the
user steps closer, the duty cycle increases. In this way, the user 110 can
control the
showerbath in a very intuitive and natural way. The volume (amount of water)
of the
flow is increased by stepping closer to the wall on which spray head 171 is
located,
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CA 02280420 1999-12-17
and decreased by moving further away.
The control signal 179 is preferably supplied to a Pulse Width Modulated (PWM)
valve. A satisfactory valve is that made by Berkurt.
Since all of the circuits are behind the tiles, the apparatus is safe from the
water
of the shower, unlike apparatus of the prior art which is often affixed to a
stainless
steel plate containing a dark viewing window, the plate being screwed to the
wall.
Moreover, the apparatus may be built into the tile itself, so that it is a
completely
sealed unit, totally sealed within the ceramic with an epoxy, or with vitreous
china.
In this way no moisture can get into the circuits.
Tiling of the shower room is a simple matter of placing one of the special
tiles
below each showerbath spray head, and tiling the rest of the wall with
ordinary tiles.
Preferably, all tiles in the shower room are identical, in appearance, so that
the special
tiles do not become a target for vandalism.
Processor 130 ideally delays signal 179 to make it difficult for a person to
move
his or her hand around on the wall to locate the tile which is controlling the
process.
A slight but random delay makes it almost impossible for user 110 to locate
the
apparatus 120 and 160 by movement of the hand in front of tiles on the wall or
the
like.
The delay also serves to prevent the showerbath spray head from turning on if
someone walks past, without planning to shower. Therefore, the user must stand
for
a few seconds under the showerbath spray head before it will turn on.
An algorithm running on processor 130 may also determine the degree of spec-
ularity of user 110 such that shower spray head 171 will not come on if user
110 is
clothed. In this way, cleaning stafF, or those who happen to pass through the
shower
area (e.g. lifeguards, etc., at a municipal swimming bath) will not be deluged
with
water. As skin is somewhat translucent in the infrared, and has other
properties
distinct from clothing, the apparatus may also use additional information of
this sort
to decide whether or not to switch on spray head 171.
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FIG. 2 depicts the timing waveforms for signal 122, beam 161, and high voltage
signal 151. Signal 140 is indicated by waveform 240. The light level of beam
161 is
indicated by wa,veform 261. The high voltage signal 151 is indicated by
waveform
251.
Preferably the tile. will appear like an ordinary white bathroom tile, which
has
the shiny appearance of vitreous china, but with an opaque and diffuse
appearance
under the surface glazing. Accordingly, the on-time 200 of these three
synchronized
waveforms should be relatively short compared to the off-time. 201. In this
way, user
110 will not be able to see thorough tiles 1_70 because they are transparent
for a very
brief interval.
Preferably images 120 operates a,t a higher frequency than standard R.S-170 de-
vices. A custom built images running at a. higher frequency, but capturing
less data
per frame, would be. less visible owing to the absence of any visible
frequency. At the
very least, it would be preferable that pulses of on-time 200 be slightly
randomized,
or not operate a.t exactly the same frequency as fluorescent lighting in the
shower
room, such that there will not be interference, or visibility of any beat
patterns in the
tiles owing to beat frequency between the frame-rate of images 120 and the
ambient
lighting in the shower room.
FIG. 3 depicts the temporally selective view diffuser of the invention, built
within
the vitreous china. of a water closet 300. Rather than having a. separate
apparatus
attached to a water closet, the apparatus is built within the china itself.
Sanita.rv
futures are generally made of a ceramic material that is called "vitreous
china",
owing to their vitreous (glasslike) nati.ire. Not surprisingly, the glassy
surface of the
water closet provides for a good environment in which to make the apparatus of
the
invention.
Preferably the apparatus is disposed on the inside of the bowl 310, and
located at
the back of the bowl 310. Here infrared rays 361 c.an emerge directly from the
vitreous
china, reflect off a user of the vitreous china, and then be absorbed and
quantified as
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CA 02280420 1999-08-12
incoming rays 321 by the <:hina.
Preferably, by locating the apparatus within the bowl, the apparatus can also
determine whether or not there is waste in the bowl, and the nature of the
waste in
the bowl to effect a flushing that is responsive to the presence of waste. and
to the
amount and type of waste in the bowl. In this way, water can be greatly
conserved
by the use of a control valve 390 that is responsive to the contents of the
bowl, and
not just the length of time that the user of the fixture has spent in
proximity thereto.
Moreover, by locating the apparatus inside the. bowl, it is muc-h less likely
that
users will tamper with it, owing to the unsanitary, or perceived unsanitary
nature of
the interior of the bowl of a, sanitary fixture. It is doubtful that users
would insert
their heads into the bowl to look closely at the apparatus, or insert their
hands into
the bowl to try to activate the apparatus superficially, either by virtue of
curiosity,
or for mischief.
FIG. 4 depicts the use of the temporally diffuse viewing window used in a
dwelling.
A nosy neighbour, warrantless police inspector, or other person 410 outside
the
dwelling cannot look in through window 470 because window 470 has a frosty ap-
pearance to person 410. Inside the dwelling, instruments 420, which are the
eyes of
the occupant, are shuttered with shuttergla,sses 425. Satisfactory
shuttergla,sses may
be made by modifying 3-D glasses such as those manufactured under the trade
name
Crystal Eyes. Alternatively, suitable electrochromic eyeglasses may be custom
made,
or an apparatus based on a heir cell ma,y be used. Alternatively, a. handheld
device
may be used in place of shutterglasses 425.
The shutterglasses are dark most of the tune, but become transparent during
brief
bursts; at which time a transmitter operating through antenna. 426 sends a,
signal 4'?7,
which is received as signal 476 by receive antenna 475. Receiver 474 applies
a, high
voltage pulse to window 470 making it transparent for the brief interval for
which the
shutterglasses 425 are transparent.
In this way, the shutterglasses 425 reduce the. overall light levels, but
remove the
CA 02280420 1999-08-12
frosty appearance of window 470 as perceived by instrument 420.
FIG. 5 depicts examples of timing waweforms for use with the dwelling window
470.
On-time .500 may be similar to that of FIG. 2, but ofI-time 501 may be
randomized.
In this way, a spy person 410 cannot simply use a signal generator fed to
shutterglasses
and try different frequencies.
The situation described above, in the content of FIG. 4 and FIG. ~, assumes
that the there is one occupant with ocular apparatus 420 wishing to be
responsive to
nonscattered light from outside the dwelling's window 470. In the event that
there
may be multiple occupants, the situation may be. reversed.
In this reversed (multiple occupant) situation, receiver 474 ma.y be replaced
in-
stead with a transmitter responsive to the transparent on-time of window 470.
Trans-
muter antenna 426 may be replaced with a receive antenna., so that
shutterglasses
42.5 are controlled by window 470, rather than vice-versa as originally
described.
FIG. 6 depicts a block diagram of a security system for the temporally diffuse
viewing window. A random pulse generator 67.0 drives a vitrionic window 620 to
which an encryptor 630 drives transmitter 640 with encrypted timecodes of
pulses.
A receiver 650 passes this information to decryptor 660, which controls
shutter-
glasses 6 7 0.
Preferably encryptor 630 also drives noise source 641 to cancel or mash the
electro-
magnetic radiation from window 470, otherwise spy person 410 could use an
antenna
to pick up the emissions of window 470 and derive clocking information for use
of
illegal shutterglasses.
Encryptor 630 ma.y broadcast a license signal, such that licensees can see
through
the glass, but those who have not obtained a license cannot see through the
glass in
a nonscattered fashion.
FIG. 7 depicts a. contact lens shutter based on a received signal that males
the
contact lens transparent when the window is transparent, and makes the.
contact lens
dark when the window is diffuse. Contact lens 700 is significantly larger than
the
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CA 02280420 1999-08-12
transparent portion of the eye responsive to light. Soft contact. lenses are
typically
very large so contact lens 700 would be of similar size. Two plates 710 and
711 made
of conductive ITO (indium-tin oxide) coatings having transmissivity in the
visible
region, a,nd typically having resistivity in the range of 10 to 10,000
ohms~square, a,re
imbedded in the contact lens but not touching each other.
The ITO (indium-tin oxide) coating is typical of what is used in LCDs (Liquid
Crystal Displays).
A firsts coating 710 is separated from a second coating 711 by an insulating
layer.
The insulating layer contains the portion of the contact lens display that is
to be
controlled or switched. A shutter ma,y thus be implemented by induced current
received in wire loop 720. Wire loop 7 20 is disposed around the periphery of
the
contact lens where the eye is not responsive to light.
In another embodiment, a, processor inside contact lens 7 00 is powered
inductively
by the wire loop 720, and the processor controls the shutter formed between
plates
710 and 711.
From the foregoing description, it will thus be evident that the present
invention
provides a, design of a contact lens for information display. As various
changes ca,n
be made in the above embodiments and operating methods without departing from
the spirit or scope of the invention, it is intended that a,ll matter
contained in the
above description or shown in the accompanying drawings should be interpreted
as
illustrative and not in a limiting sense.
Variations or modifications to the design and construction of this invention,
within
the scope of the invention, may occur to those skilled in the art upon
reviewing
the disclosure herein. Such variations or modifications, if within the spirit
of this
invention, are intended to be encompassed within the scope. of any claims to
patent
protection issuing upon this invention.
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