HK1108858B - One-way viewable screen - Google Patents

Description

One-way visual screen

Technical Field

The invention relates to a one-way visual screen.

Background

Fences are commonly used in a variety of situations to define property boundaries, or to maintain people, animals, and/or objects inside or outside the property. Conventional barriers are generally configured in two forms: the two-way vision (the people at the two sides of the fence can both see through) or the non-vision (the people at the two sides of the fence can not see through under the condition of hiding the fence).

Similarly, screens and partitions are often provided that are not visible, thereby blocking clear perspective to the other side by persons on either side of the screen. In some cases, a one-way visual screen or mirror has been provided. In particular, in some department stores, nurseries and witness challenge rooms, it is sometimes desirable to provide a one-way mirror so that others outdoors can observe what is happening indoors, while those observed indoors cannot see their observers. The half-mirror only works when the lighting conditions on one side are much stronger than on the other side. It will be readily appreciated that such a one-way glass mirror is so rigid and fragile that it can only be used in special environments, such as along a rigid wall.

Other unidirectional visual materials, such as porous ethylene, are designed for situations where the lighting conditions on both sides of the material are very different. (e.g., such materials are typically used for building or automotive glazing where the light inside the structure adjacent one side of the material is significantly different from the light outside the structure adjacent the other side of the material.) these panel materials typically have a see-through open area of about 30 to 50% containing a plurality of relatively large openings (e.g., circular openings of about 1mm in diameter.) but, when the lighting conditions on both sides are approximately equal, they do not provide suitable one-way see-through.

Examples of such porous vinyl, printed film and translucent metal coatings on glass for providing one-way see-through are described in U.S. patent nos. 5,925,437, 6,258,429 and 4,673,609. As previously mentioned, such materials do not provide one-way visibility when the illumination on both sides of the material is approximately equal.

Disclosure of Invention

The present invention relates to a fence, screen, divider or the like which provides one-way visibility characteristics under approximately equal lighting conditions on both sides of the structure. (As used herein, such structures will be collectively referred to as "screens"). As previously mentioned, prior art one-way vision structures are not capable of one-way vision when the illumination on both sides of the structure is approximately equal. In fact, the inventors have found that conventional materials have an optical path equivalent to at least about 30-50% light transmission (e.g., by calculating the percentage of open area and assuming transmission occurs only through the open area, 1mm diameter holes spaced 1.4mm apart were found to be equivalent to about 40% light transmission; 1/16 inch diameter holes spaced 3/32 inches apart were found to be equivalent to about 35% light transmission). However, it has been found thatSuch a high level of light transmission does not provide opacity in one direction, regardless of how the material is reflected, under equivalent lighting conditions. It is preferred that the area of the opening in a screen of the present invention is greater than the area of a circular opening having a diameter of 1mm (i.e., 0.785mm²) And is smaller. Preferably less than 0.2mm²(area of circle having a diameter of 0.55 mm), even more preferably 0.07mm²(area of circle having a diameter of 0.3 mm). However, other sizes and shapes of openings may be used within the scope of the present invention.

In addition to providing the advantage of one-way visibility under similar lighting conditions on both sides of the structure, the present invention also provides good breathability and high mechanical strength in most cases without the need for a perforation manufacturing step.

Screens are designed for optimal performance when the light intensity is greater than 20 Lux. As previously mentioned, the screen of the present invention works well when the light intensity is approximately equal on both sides of the screen. However, it has also been found that: the screen also works well when the light intensity on the reflective side is greater than the light intensity on the highly absorbing (i.e., less reflective) side. Note that: ranges of light transmission values and ratios of light reflection to light transmission are described; it is easy to understand that the see-through and blocking performance are affected by light intensity. For example, when the light intensity is brighter rather than relatively low, a greater see-through capability is generally achieved.

The light transmission of the screens of the present invention in the 400-700nm spectrum (i.e., the visible spectrum) is desirably from about 2.8 to about 25%. The screen also has a first side having a total light reflection to light transmission ratio > 2.5 and a second side having a total light reflection to light transmission ratio < 2.

Drawings

FIG. 1 is a perspective view of a screen according to the present invention;

FIG. 2 is a photomicrograph of a woven version of a structure according to the invention;

FIG. 3 is a photomicrograph of a knit layout of a structure according to the invention to illustrate alternative opening distributions and sizes;

FIG. 4 is a schematic view of the screen of FIG. 1 illustrating light transmission, reflection, and absorption;

FIG. 5 is a cross-sectional view of an alternative embodiment of the present invention;

FIG. 6 is a cross-sectional view of a tufted version of the fabric of the invention;

fig. 7 is a cross-sectional view of a woven fabric according to the present invention.

Detailed Description

In the following detailed description of the present invention, certain preferred embodiments of the present invention are described in order to provide a thorough understanding of the present invention. It will be understood that it is not intended to limit the invention to the particular preferred embodiment described, and although specific terms are employed in describing the invention, they are used in a descriptive sense for purposes of illustration and not for purposes of limitation.

Referring to the drawings, FIG. 1 is a perspective view of a screen 10 according to the present invention, in this view in the form of a fence. As shown, the fence includes a brace 16, with a fastener 18 securing the material to the brace 16. (as one of ordinary skill in the art will readily recognize, the screen may be constructed in any shape or pattern, fig. 1 merely generally showing how the material is oriented so that each of its two sides is exposed to substantially the same light.) the screen 10 includes a first side 12, which is designed as an opaque side, and a second side 14, which is designed as a see-through side. When the screen is used under conditions where the illumination on both sides is approximately equal, an observer looking at the 12 side of the screen will not be able to see through the screen, while an observer looking at the 14 side will be able to see through the screen.

As will be appreciated by those of ordinary skill in the art, when an observer sees a structure such as a screen, only things on the opposite side of the screen can be seen because light is transmitted through the screen from the opposite side. As shown in fig. 4, both sides of material F are exposed to substantially the same amount of light, because all of the amount of light is transmitted through, reflected back from, or absorbed by the screen:

T1-T2, and T2+ R2+ a 2-100%, and T1+ R1+ a 1-100%, wherein

T1 ═ light transmitted through side 12;

r1 ═ light reflected by side 12;

a1 ═ light absorbed by side 12;

t2 ═ light transmitted through side 14;

r2 ═ the light reflected by the 14 side;

a2 is the light absorbed by the 14 side.

The inventors have found that by having a fabric with a light transmission in the 400-700nm spectrum of about 2.8% to about 25%, and having a total light reflection to light transmission ratio of > 2.5 for the first side of the screen and a total light reflection to light transmission ratio of < 2 for the second side of the screen, the following screens can be obtained: one side of which has good opacity (i.e., blocking) and the other side has good transparency when both sides are exposed to substantially the same amount of light.

The invention is characterized in that: the fabric structure has a light transmission in the 400-700nm spectrum of about 2.8 to about 25%. (for the purposes of this application, the light transmission in the visible spectrum is obtained by measuring the light transmission from 400-700nm per 10nm wavelength using a spectrophotometer in the conventional manner, with the measured light transmission and light reflection being taken as a percentage of the incident light beam.) even more preferably, the structure has a light transmission in the 400-700nm spectrum of about 15% or less. In addition, the fabric has two sides with very different optical properties, wherein the ratio of total light reflection to light transmission on one side of the fabric is at least 2.5, preferably about 5 or more, more preferably about 10 or more, and the ratio on the other side of the fabric is about 2 or less, more preferably about 1.5 or less. It is also highly preferred that the light absorption on the highly reflective side is as small as possible, while the light absorption on the other side is as large as possible. (As previously mentioned, total light is the sum of the light transmitted through the fabric plus the light reflected back by the fabric and the amount of light absorbed by the fabric.

In addition to light transmission of about 2.8-25%, the size of the openings in the material is desirably small (as described above), with the openings being relatively uniformly distributed throughout the material. It has also been found that this combination provides particularly good perspective. When larger size orifices are used in combination with the above-mentioned low level of all openings, fewer orifices are needed and the orifices are spaced further apart. As a result, it was found that: regardless of whether the material has other optical properties, the viewer has limited partial light transmission and cannot put the entire picture on the other side of the material together. Therefore, the opening size of the present invention is preferably 0.7mm²Or less, more preferably 0.07mm²Or smaller and ideally the openings are distributed very evenly over the entire size of the material for which the perspective is designed. In most cases, it is desirable that the overall size of the structure be transparent in the case where the openings are distributed over the overall size of the material. However, in another aspect of the invention, the see-through portion of the material may be disposed adjacent to the non-see-through region. For example, a lattice structure formed of areas without openings may be formed to provide additional strength to the material, to provide special designs, and the like.

The total light transmission through the fabric structure is about 2.8-25%, such light transmission preferably being achieved by controlling the yarn density such that the openings between the yarn interstices of the fabric structure provide a desired level of light transmission. The fabric may be of any type, including woven, knitted or non-woven. In a preferred form of the invention designed to perform well in environments where high strength is required, a warp knit structure is preferred. Alternatively, perforations, coatings and printing may also be used to create light paths or partially blocked light paths to control the level of light transmission. However, since the perforations generate waste and significantly reduce the strength of the material, they are generally not preferred in applications requiring high mechanical strength (e.g., fencing and insulation).

Light reflection may be achieved with one or more of the following: white fiber/fabric surface; coatings on fabrics containing reflective substances such as titanium dioxide, zinc oxide, zirconium oxide, barium sulfate, calcium carbonate, magnesium carbonate, calcium phosphate, mica, metallic pigments (e.g., balun and brass); metallic coatings such as sputtered or hot vapor deposits of aluminum on fabric structures, or electroless plating of silver, chromium or similar reflective materials. Fibers or ribbon-like fibers having a trilobal cross-section may also be used to provide high reflection.

These materials are capable of absorbing ultraviolet light energy and emitting the energy as visible light, thus providing improved brightness to the human eye.

Low reflection can be achieved by a dark textile surface or by dyeing, printing or coating with a material having high light absorption properties. High light absorption can be achieved by using one or more of the following: dark dyes and/or pigments such as carbon black, iron oxide and graphite.

In one embodiment, the fabric structure of the present invention is provided in the following manner: a warp knitting process is used to form a fabric structure, the fabric is dyed a jet black color, and one side of the fabric is coated with a reflective coating such as a mixture of polyacrylic resin and titanium dioxide pigments. The warp knitting process provides sufficient yarn density such that light transmission through the structure is 25% or less, the coating provides high total reflection on one side of the fabric, and the black dye provides high light absorption on the opposite surface. Alternatively, the fabric may be formed from pre-dyed or spun-dyed fibers, or coated with a coating without being initially dyed.

In another embodiment, white or other light colored fabrics are stitched, laminated, or otherwise affixed to a dark colored highly light absorbing fabric to form a two layer composite such that the overall composite has a light transmission in the visible wavelength range of 25% or less, a white-side reflection to transmission ratio of at least 2.5, and a dark-side ratio of about 2 or less. Such textile structures may be formed using textile construction techniques with no or minimal further processing. For example, reflective white or light colored yarns and dark colored highly light absorbing yarns, for example, can be woven or knitted into such fabrics: so that the light/white yarns are distributed mainly on one side and the dark yarns are distributed mainly on the other side. Ideally, the fabric is formed to have a yarn density of: such that the total light transmission through the finished fabric is less than about 25%. Alternatively, satin, dobby, jacquard, plain, basket, etc. may be used to weave the following single or double layer fabrics: wherein the light colored yarns are distributed predominantly on one side of the fabric and the dark colored highly light absorbing yarns are distributed predominantly on the other side. For example, in satin weaves, white trilobal yarns may be used as warp yarns and spun-dyed jet-black yarns may be used as weft yarns, such that white warp yarns are distributed predominantly on one side and jet-black yarns are distributed predominantly on the other side. Alternatively, knitted fabrics having a highly reflective side and a highly light absorbing side can also be formed by using warp knitting and double-needle comb knitting. When using weaving or knitting techniques to provide the reflective yarn on one side and the light-absorbing yarn on the other side, a double-layer fabric is preferred.

In a further embodiment shown in fig. 5, a pile fabric is formed, wherein the pile yarns are reflective light colored yarns (reflective light colored yarns) and the ground yarns on the other side of the fabric (base yarns) are dark colored with high light absorbing properties. As shown in fig. 5, a fabric, generally indicated at 20, includes a ground yarn structure 22, and a pile formed from a plurality of fiber bundles 24. Thus, the pile construction of one side provides high total light reflection characteristics, while the bottom of the fabric has openings (between the yarns and bundles of the bottom structure) to facilitate perspective viewing of the fabric side adjacent to the ground yarn structure. This "tapered" type of cross-section of the fabric structure (the "taper" formed between adjacent tufts) is desirable in enhancing the one-way perspective. Further, a light absorbing coating or the like may be provided on the ground yarn 22 and the portion of the yarn bundle in contact with the ground yarn.

Figure 6 illustrates the fabric shown in figure 5 depicting the O-shaped openings that exist between the yarns forming the fabric. Similarly, fig. 7 illustrates a woven fabric depicting the O-shaped openings that occur between adjacent yarns forming the fabric and showing the different sides 12, 14 (as shown in fig. 1 and 4).

This pattern can significantly improve the opacity characteristics on the highly reflective side. Jacquard weaving, double needle bar weaving, dobby jacquard weaving, pattern sanding, laser etching, embossing, and the like.

The light transmission and reflection of such fabric structures can be measured using a spectrophotometer such as the Jasco V-570 spectrophotometer available from Jasco corporation of iston, maryland using incident light at visible wavelengths of 400nm to 700 nm.

Other features such as infrared features, infrared absorption, reflection, and infrared fluorescence can also be introduced on one or both sides of the fabric by using infrared reflective pigments, carbon black, or infrared absorbing/fluorescent dyes. Further, patterns (designs) may be provided on one or both surfaces of the fabric by printing, embossing, painting or other means, as desired, provided that the patterns do not interfere to the extent that reflection, transmission and absorption are not achieved.

Example (b):

example 1: a weft flat warp knit fabric having 24 wales per inch x 28 wales per inch was formed using a 3 comb 1/150/2456T (meaning 1 ply, 150 denier yarn, each yarn having 24 filaments, Dacron type 56 round cross section polyester yarn) yarn and a1 comb 1/100/3456T ground yarn. The fabric weighed approximately 8.88 ounces per square yard. As shown in FIG. 3, the fabric has gap openings varying at most in the range of 0.1-0.25mm and spaced from each other by approximately 0.3-2 mm. The fabric was then jet-dyed to a deep black color using a black disperse dye according to conventional methods to achieve low reflection in the visible spectrum (close to 4%). The fabric is then heat-set on a stenter frame according to conventional methods. A metal polish paint containing an aluminum reflective pigment produced by Rust-Oleum Corporation was used to paint one side of the fabric so that the side was covered with the metallic paint. The air permeability of the coated fabric was approximately 135cfm at a pressure of 125Pa using ASTM D737-96. The fabric was held vertically in both indoor and outdoor positions so that both sides of the fabric were under similar lighting conditions. Observations were made 10 to 20 feet from either side of the fabric to determine one-way perspective. The fabric provides good see-through on the uncoated black side, but is substantially opaque on the coated side, when both sides of the fabric are under equal lighting conditions, indoors or outdoors.

Example 2: the same warp knit fabric as used in example 1 was changed to a nearly white cream color dyed with disperse dye. The fabric is then heat-set on a stenter frame according to conventional methods. A metal polish spray paint produced by the Rust-Oleum Corporation (of the same type as used in example 1) was then used to paint a metal reflective coating on one side of the fabric, while the other side of the fabric was coated with a jet black semi-gloss spray paint of the variety sold under the trade name Krylon by Sherwin-Williams Corporation. When examined in the same manner as described in example 1, the coated fabric exhibited substantially no perspective on the metal coated side and good perspective on the black coated side under the condition that the light conditions were equal on both sides of the indoor and outdoor fabrics.

Example 3: the same near white cream colored warp knit fabric from example 2 was used. One side of the fabric was coated with a jet of dark semi-gloss Krylon spray paint. The black coated side provides high light absorption and good see-through characteristics. Interestingly, no reflective treatment is required on the other side, which is a near white textile surface sufficient to reflect to provide opacity.

Example 4: the woven fabric was formed with a single 574 denier polyester monofilament warp yarn and a single 535 denier monofilament Nylon 6 weft yarn. The fabric was woven in a plain weave pattern with 34 picks per inch and 35 ends per inch. A black coating was applied on one side using a semi-gloss Krylon black paint. The other side was coated with a 1: 1 ratio mixture of Melalite Ultra Bright UMA (manufactured by Engelhardcorporation) and polyurethane latex Implanil 85UD (manufactured by Bayer Corp, Levokusen, Germany). Mearlite Ultra Bright UMA is an aqueous dispersion of a mica reflective pigment coated with titanium dioxide. The fabric was found to have no good opacity on the reflective side, which the inventors believe was due to the high level of openness. Due to the relatively high open area of the fabric structure, the resulting fabric does not have good opacity on the highly reflective side of the fabric, although the opacity is clearly obscured from view from the reflective side. This can be seen from the low reflection to transmission ratio on the reflective side, which is 2.37.

Example 5: a black Activated carbon woven fabric, FM1/250 (manufactured by Activated charcoalInternational, UK), was coated on only one side with a metal polish spray paint manufactured by Rust-Oleum Corporation. Black activated carbon fibers provide high light absorption characteristics on the other side. The interstices between the warp and weft yarns provide light transmission. The coated fabric has good one-way perspective property under indoor and outdoor illumination conditions. The fabric had void openings with openings of about 0.2-0.35mm (the dimension transverse to the rectangular holes) and about 0.8-1mm apart.

Example 6: a woven short fiber polyester fabric having 204 denier short fiber warp yarns and 12 denier short fiber weft yarns and having a plain weave pattern of 55 weft yarns/inch and 68 warp yarns/inch was dyed in deep black with a black disperse dye. Subsequently, one side of the fabric was coated with a metallic polish spray paint manufactured by Rust-Oleum Corporation. The fabric only shows see-through under outdoor high intensity lighting conditions. Spun yarn texture and too low a level of light transmission make the fabric unsuitable for use in one-way vision under low light intensity conditions.

Light transmission and reflection measurements were performed using a Jasco V-570 visible/UV/NIR spectrophotometer. Only visible light transmission and reflection occurs. The results are listed in the following table. It was found that these embodiments performed well in perspective from only one side of the fabric when both sides of the fabric were exposed to the same light conditions, and that these embodiments exhibited light transmission of about 2.8% to about 25%, with a first side having a total light reflection to light transmission ratio > 2.5 and a second side having a total light reflection to light transmission ratio < 2. Example #4 illustrates the upper limit of light transmission that is opaque on the reflective side, and example #6 illustrates the lower limit of light transmission that is required for transmission on the absorptive side.

Example 1 results

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						700	3.881	31.692	9.772	8.165936614	2.517907756
690	3.695	32.161	8.144	8.703924222	2.20405954
						680	3.454	31.774	6.622	9.199189346	1.917197452
670	3.242	31.35	5.396	9.669956817	1.664404688
						660	3.122	31.241	4.663	10.00672646	1.49359385
650	3.043	31.167	4.226	10.2421952	1.388761091
						640	3.002	31.147	4.003	10.37541639	1.33344437
630	2.987	31.159	3.916	10.43153666	1.311014396
						620	2.982	31.19	3.906	10.45942321	1.309859155
610	2.984	31.231	3.926	10.46615282	1.315683646
						600	2.983	31.264	3.94	10.4807241	1.320817968

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						590	2.984	31.3	3.961	10.48927614	1.327412869
580	2.986	31.329	3.992	10.49196249	1.336905559
						570	2.983	31.358	3.997	10.512236	1.339926249
560	2.977	31.371	3.969	10.53778972	1.333221364
						550	2.973	31.391	3.962	10.55869492	1.332660612
540	2.972	31.408	3.97	10.5679677	1.335800808
						530	2.967	31.422	3.951	10.59049545	1.331648129
520	2.954	31.404	3.917	10.6310088	1.325998646
						510	2.952	31.429	3.926	10.64668022	1.329945799
500	2.951	31.459	3.949	10.66045408	1.338190444
						490	2.946	31.477	3.953	10.68465716	1.341819416
480	2.938	31.495	3.956	10.71987747	1.346494214
						470	2.94	31.556	3.974	10.73333333	1.35170068
460	2.956	31.747	4.002	10.73985115	1.353856563
						450	2.967	31.905	4.032	10.75328615	1.358948433
440	2.949	31.785	4.025	10.77822991	1.364869447
						430	2.924	31.684	3.998	10.83584131	1.367305062
420	2.921	31.761	4.04	10.87333105	1.383087984
						410	2.913	31.714	4.112	10.88705802	1.411603158
400	2.919	31.797	4.25	10.89311408	1.455978075
						Mean value of	3.046677419	31.48929032	4.466129032	10.3802041	1.446584433

Example 2 results

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						700	3.021	32.772	3.579	10.84806356	1.184707051
690	3.108	33.54	3.666	10.79150579	1.17953668
						680	3.1	33.656	3.636	10.85677419	1.172903226
670	3.066	33.576	3.592	10.95107632	1.171559035
						660	3.061	33.66	3.591	10.9964064	1.173146031
650	3.053	33.747	3.59	11.05371765	1.175892565
						640	3.046	33.826	3.591	11.10505581	1.178923178
630	3.04	33.905	3.591	11.15296053	1.18125
						620	3.037	33.981	3.592	11.1890023	1.182746131
610	3.032	34.053	3.593	11.23120053	1.185026385
						600	3.027	34.126	3.595	11.27386852	1.187644533
590	3.02	34.183	3.598	11.31887417	1.191390728
						580	3.015	34243	3.6	11.35754561	1.194029851
570	3.01	34.287	3.601	11.3910299	1.196345515
						560	3.002	34.335	3.606	11.43737508	1.201199201
550	2.996	34.384	3.61	11.47663551	1.20493992
						540	2.992	34.432	3.614	11.50802139	1.207887701
530	2.987	34.473	3.619	11.54101105	1.211583529
						520	2.974	34.485	3.624	11.59549428	1.218560861
510	2.971	34.529	3.633	11.62201279	1.222820599
						500	2.962	34.571	3.643	11.67150574	1.229912221

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						490	2.955	34.593	3.655	11.70659898	1.236886633
480	2.946	34.612	3.667	11.74881195	1.244738629
						470	2.941	34.652	3.687	11.78238694	1.253655219
460	2.951	34.857	3.722	11.81192816	1.261267367
						450	2.965	35.115	3.747	11.84317032	1.263743676
440	2.945	35.117	3.742	11.92427844	1.270628183
						430	2.92	35.01	3.749	11.98972603	1.28390411
420	2.915	35.106	3.777	12.0432247	1.295711835
						410	2.896	35.119	3.78	12.12672652	1.305248619
400	2.881	35.15	3.809	12.20062478	1.322110378
						Mean value of	2.994677419	34.32564516	3.648354839	11.46924561	1.219029019

Example 3 results

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						700	4.642	42.569	3.574	9.170400689	0.769926756
690	4.715	43.54	3.649	9.234358431	0.773913043
						680	4.681	43.756	3.606	9.347575304	0.770348216
670	4.623	43.592	3.568	9.429374865	0.771793208
						660	4.605	43.679	3.564	9.485124864	0.773941368
650	4.586	43.769	3.557	9.5440471	0.775621457
						640	4.568	43.855	3.553	9.600481611	0.777802102
630	4.55	43.945	3.549	9.658241758	0.78

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						620	4.531	44.044	3.547	9.720591481	0.782829397
610	4.512	44.138	3.543	9.782358156	0.785239362
						600	4.491	44.265	3.541	9.856379426	0.788465821
590	4.475	44.387	3.539	9.918882682	0.790837989
						580	4.456	44.47	3.538	9.979802513	0.793985637
570	4.432	44.492	3.535	10.03880866	0.797608303
						560	4.404	44.512	3.532	10.1071753	0.801998183
550	4.386	44.596	3.532	10.16780666	0.805289558
						540	4.364	44.723	3.534	10.24816682	0.809807516
530	4.342	44.823	3.536	10.32312298	0.814371257
						520	4.314	44.87	3.536	10.40101994	0.819656931
510	4.289	45.017	3.54	10.49591979	0.825367218
						500	4.267	45.149	3.546	10.58097024	0.831028826
490	4.239	45.193	3.553	10.66124086	0.83816938
						480	4.209	45.207	3.561	10.74055595	0.846044191
470	4.182	45.276	3.577	10.82639885	0.855332377
						460	4.17	45.594	3.608	10.93381295	0.865227818
450	4.159	46.009	3.629	11.06251503	0.872565521
						440	4.115	46.07	3.616	11.19562576	0.87873633
430	4.062	45.956	3.62	11.3136386	0.891186608
						420	4.034	46.051	3.642	11.41571641	0.902825979
410	3.967	45.844	3.64	11.5563398	0.917569952

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						400	3.909	45.411	3.655	11.61703761	0.935021745
Mean value of	4.36383871	44.67103226	3.571612903	10.27140294	0.820726195

Example 4 results

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						700	27.302	65.82	16.763	2.410812395	0.613984323
690	26.998	65.826	16.559	2.438180606	0.613341729
						680	26.893	65.706	16.359	2.443238017	0.608299558
670	26.836	65.349	16.046	2.43512446	0.597928156
						660	26.76	65.081	15.766	2.432025411	0.58916293
650	26.651	64.791	15.462	2.431090766	0.580165847
						640	26.52	64.494	15.09	2.431900452	0.569004525
630	26.399	64.133	14.639	2.429372325	0.554528581
						620	26.268	63.727	14.087	2.426031674	0.536279884
610	26.113	63.34	13.524	2.425611764	0.51790296
						600	25.994	62.939	13.077	2.421289528	0.503077633
590	25.914	62.617	12.827	2.416338659	0.494983407
						580	25.887	62.286	12.697	2.406072546	0.490477846
570	25.838	61.926	12.563	2.396702531	0.486221844
						560	25.787	61.556	12.423	2.387094272	0.481754372
550	25.726	61258	12.336	2.3811708	0.479514888
						540	25.681	60.981	12.304	2.374557066	0.479109069

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						530	25.666	60.735	12.338	2.366360165	0.480713785
520	25.626	60.464	12.365	2.359478654	0.482517755
						510	25.6	60.23	12.365	2.352734375	0.483007813
500	25.558	59.927	12.311	2.344745285	0.481688708
						490	25.515	59.627	12.203	2.336939055	0.478267686
480	25.473	59.35	12.078	2.329917952	0.474149099
						470	25.403	59.058	11.958	2.324843522	0.470731803
460	25.251	58.787	11.865	2.328105818	0.469882381
						450	25.079	58.416	11.791	2.329279477	0.470154312
440	25.037	57.878	11.675	2.311698686	0.466309861
						430	25.035	57.385	11.603	2.292190933	0.46347114
420	24.994	56.855	11.513	2.274745939	0.460630551
						410	24.903	55.985	11.389	2.248122716	0.457334458
400	24.738	54.299	11.082	2.194963214	0.447974776
						Mean value of	25.85306452	61.31696774	13.19541935	2.370346421	0.509115216

Example 5 results

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						700	3.734	34.063	3.167	9.122388859	0.848152116
690	3.688	34.209	3.148	9.275759219	0.853579176
						680	3.67	34.423	3.164	9.379564033	0.862125341
670	3.68	34.469	3.147	9.366576087	0.855163043

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						660	3.681	34.548	3.128	9.385493073	0.849769084
650	3.687	34.617	3.117	9.388934093	0.845402766
						640	3.689	34.689	3.106	9.403361345	0.841962591
630	3.687	34.759	3.088	9.42744779	0.837537293
						620	3.697	34.811	3.07	9.416012984	0.830403029
610	3.702	34.851	3.055	9.414100486	0.825229606
						600	3.706	34.919	3.037	9.422288181	0.819481921
590	3.71	34.967	3.032	9.425067385	0.817250674
						580	3.71	35.015	3.013	9.438005391	0.81212938
570	3.714	35.054	3.001	9.438341411	0.808023694
						560	3.716	35.065	2.985	9.436221744	0.8032831
550	3.718	35.109	2.971	9.442980097	0.79908553
						540	3.723	35.135	2.956	9.437281762	0.793983347
530	3.723	35.161	2.941	9.444265377	0.789954338
						520	3.727	35.175	2.923	9.437885699	0.784276898
510	3.725	35.197	2.909	9.44885906	0.780939597
						500	3.731	35.213	2.894	9.437952292	0.775663361
490	3.733	35.233	2.878	9.438253415	0.770961693
						480	3.737	35.247	2.863	9.431897244	0.766122558
470	3.736	35.255	2.85	9.436563169	0.762847966
						460	3.712	35.287	2.833	9.506196121	0.763200431
450	3.682	35.382	2.827	9.609451385	0.767789245

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						440	3.691	35.429	2.83	9.598753725	0.766729884
430	3.698	35.422	2.813	9.578691184	0.760681449
						420	3.71	35.489	2.812	9.565768194	0.757951482
410	3.698	35.538	2.809	9.610059492	0.759599784
						400	3.69	35.558	2.79	9.636314363	0.756097561
Mean value of	3.706612903	35.00932258	2.972806452	9.445184989	0.802108966

Example 6 results

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						700	6.178	22.784	14.835	3.687924895	2.401262545
690	5.042	21.683	10.542	4.300476002	2.090836969
						680	4.048	20.521	7.163	5.069416996	1.76951581
670	3.313	19.535	4.984	5.896468458	1.504376698
						660	2.863	18.911	3.828	6.605309116	1.337059029
650	2.623	18.523	3.279	7.061761342	1.250095311
						640	2.507	18.355	3.027	7.321499801	1.207419226
630	2.455	18.289	2.922	7.449694501	1.190224033
						620	2.436	18.295	2.891	7.510262726	1.186781609
610	2.432	18.329	2.894	7.536595395	1.189967105
						600	2.434	18.363	2.906	7.544371405	1.193919474
590	2.433	18.395	2.919	7.560624743	1.199753391
						580	2.445	18.439	2.945	7.541513292	1.204498978

Wavelength nm	Light transmission%	Side light reflection of A%	Light reflection of side B%	Ratio of A side	Ratio of B side
						570	2.449	18.472	2.975	7.542670478	1.214781543
560	2.456	18.511	2.998	7.537052117	1.220684039
						550	2.465	18.542	3.024	7.522109533	1.226774848
540	2.48	18.6	3.075	7.5	1.239919355
						530	2.511	18.671	3.157	7.435682995	1.257268021
520	2.557	18.792	3.272	7.349237388	1.27962456
						510	2.609	18919	3.437	7.251437332	1.317362974
500	2.685	19.093	3.65	7.110986965	1.359404097
						490	2.758	19.247	3.866	6.978607687	1.401740392
480	2.752	19.271	3.898	7.002543605	1.416424419
						470	2.653	19.119	3.668	7.206558613	1.382585752
460	2.57	18.989	3.465	7.388715953	1.348249027
						450	2.533	18.957	3.377	7.484011054	1.333201737
440	2.501	18.904	3.332	7.558576569	1.332267093
						430	2.521	18.952	3.422	7.517651726	1.357397858
420	2.584	19.177	3.645	7.421439628	1.410603715
						410	2.686	19.373	3.957	7.212583768	1.473194341
400	2.853	19.718	4.51	6.911321416	1.580792149
						Mean value of	2.833290323	19.08803226	4.124612903	7.00055179	1.383160842

As described above, the present inventors found that: the following screens provide good see-through from one side and good blocking (i.e., non-see-through) from the opposite side: the screen has a light transmission in the 400-700nm spectrum of about 2.8 to about 25%, a total light reflection to light transmission ratio on the first side of > 2.5, and a total light reflection to light transmission ratio on the second side of < 2.

The fabric structure may be used in a variety of end uses including, but not limited to, fences, barriers in buildings and road construction sites (as a safety curtain or panel to isolate accident sites), indoor partitions, and the like.

In the specification, there has been described a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Claims (4)

1. A screen having one-way visibility when both sides are exposed to light of substantially the same intensity, comprising a knitted or woven fabric having a first fabric side and a second fabric side: the knitted or woven fabric has a light transmission of 3-15% in the spectrum of 400-700nm, the first fabric side comprises a coating comprising a reflective material, and the ratio of the total light reflection to the light transmission of the first fabric side is not less than 5, the second fabric side comprises a dark dye or a dark pigment, and the ratio of the total light reflection to the light transmission of the second fabric side is not more than 1.5, wherein the fabric comprises a plurality of openings, the dimensions of the openings being such that the dimensions of the openings are not more than 1.5Cun is less than 0.2mm²Wherein the light absorption on the second fabric side is greater than 80%.

2. A screen according to claim 1, wherein said first fabric side has a light absorption of 60% or less.

3. A screen according to claim 1, wherein said material includes a plurality of openings, said openings being less than 0.07mm in size²。

4. A screen according to claim 1, wherein said plurality of openings are relatively evenly distributed throughout said fabric.