CA2280420A1 - Selective vitrionic viewing concealed by material such as polymer diffuser - Google Patents

Abstract

The temporally selective view diffuser is a system that allows an optical instrument or a person using special viewing apparatus (handheld device, special eyeglasses, special contact lens, or the like) to view through a surface that appears to other people as if it were a diffuse or opaque surface. The invention allows optical instruments such as optical motion detectors, optical flow detectors, presence detectors that require a nonscattered view, imaging systems, etc., to be concealed behind an apparently opaque or diffuse surface having the appearance of a white or coloured ceramic tile, white or coloured vitreous china, or the like.

Description

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 .7 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 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 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.
J

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, CA 02280420 1999-12-17 ~er~, ''~1~"' ~,~~i PROFr," c yv ~ cLLECTU~
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q~-11-1~~0 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, 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.

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 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 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 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.

Claims (20)

1. A vitrionic system for concealment of optical instruments comprising:
~ a material having at least two states, a first of said at least two states being a state in which light is scattered to a greater degree, and a second of said at least two states being a state in which light is scattered to a lesser degree;
~ an optical instrument; said optical instrument being more responsive to light during said second state.

2. The vitrionic system of Claim 1, where said material includes polymer dispersed liquid crystal.

3. The vitrionic system of Claim 1, where said optical instrument is an imager.

4. The vitrionic system of Claim 3 where said imager is a video camera.

5. The vitrionic system of Claim 3 further including a processor responsive to an output of said imager.

6. The vitrionic system of Claim 5 said material responsive to an output of said processor.

7. The vitrionic system of Claim 6 further including a fluid valve, said fluid valve responsive to another output of said processor.

8. A sanitary fixture incorporating the vitrionic system of Claim 7 said valve controlling the flushing of said sanitary fixture.

9. A sanitary fixture incorporating the vitrionic system of Claim 7 where said valve controls the flow of water to said sanitary fixture.

10. The vitrionic system of Claim 1, where said optical instrument is at least one eye of at least one person.

11. The vitrionic system of Claim 1, where said optical instrument is the eyes of one or more persons.

12. The vitrionic system of Claim 10 further including shutterglasses for wearing by said at least one person.

13. The vitrionic system of Claim 11 further including at least one transmitter responsive to the state of said material.

14. The vitrionic system of Claim 10 further including at least one shuttered contact lens for wearing by said at least one person.

15. The vitrionic system of Claim 1, further including an encrypter.

16. A vitrionic device containing concealed optical instrumentation, said vitrionic device comprising:
~ a vitrionic material;
~ an optical instrument concealed by said vitrionic material;
~ a synchronizer for synchronizing said optical instrument to a property of said vitrionic material.

17. A vitrionic device containing concealed optical instrumentation, said vitrionic device comprising:
~ a vitrionic material;
~ an optical instrument concealed by said vitrionic material;
~ means for synchronizing said optical instrument to a degree of diffusivity of said vitrionic material.

18. A vitrionic system for concealment of optical sensing instruments, said vitrionic system comprising:

~ a material having a translucent diffuse state, and a transparent non-diffuse state;
~ an optical sensing instrument; said optical sensing instrument being more responsive to light during said transparent non-diffuse state.

19. The vitrionic system of Claim 18 where said optical sensing instrument is a video camera.

20. A vitrionic system for concealment of a camera, said vitrionic system comprising:
~ a material having a translucent diffuse state, and a transparent non-diffuse state;
~ a camera. located behind said material;
said camera including an electronic shutter, said shutter being synchronized with a signal, said signal selecting between said translucent diffuse state, and said transparent non-diffuse state.