A sunshade composed of a transparent substrate, a first base and a second base which are provided on the both surfaces of the substrate, an infrared ray-reflecting layer which is provided on the first base and which reflects infrared rays, and a sun light-reflecting layer which is provided on the second base and which reflects a sun radiant energy with partly transmitting visible rays. The infrared ray-reflecting layer may optionally be coated with a protective layer. At least one of the protective layer, the first base and the second base has a rough surface which may diffusively reflect the light as reflected by the infrared ray-reflecting layer and the sun light-reflecting layer. In place of formation of the rough surface, a light-diffusing agent may be incorporated into the substrate, the both bases or the protective layer.

FIELD OF THE INVENTION 
The present invention relates to sunshades and, in particular, to those 
capable of properly controlling a sun light as shining into rooms, for 
example, horizontal or vertical blind slats, curtain clothes, roll blind 
clothes, exterior louvers, pent roofs, lighting top lights, sun roofs, 
transparent roofs, window glasses, etc. 
DESCRIPTION OF THE RELATED ART 
As one kind of blind slats, a slat as composed of a transparent synthetic 
resin substrate, one surface of which has been processed to have a sun 
light-reflecting layer made of a thin metal film capable of properly 
reflecting a sun light and the other surface of which has been processed 
to have an infrared ray-reflecting layer for reflecting an outdoor radiant 
heat, has been proposed. The slat of the kind may partly transit a visible 
ray therethrough, and therefore, in a day time while the outdoor area is 
lighter than the indoor area, it is possible to see outdoor views through 
a blind composed of the slats of the kind even when the blind is in a 
completely shut state. In addition, the slat has a function of properly 
controlling a visible ray with shielding a sun light heat in a summer time 
and additionally a function of elevating a room-heating effect by 
preventing transmission of an indoor radiant with properly controlling a 
visible ray to penetrate therethrough in a winter time. 
However, the slat of the said kind positively reflects an indoor light 
because of the sun light-reflecting layer and the infrared ray-reflecting 
layer. Particularly in the night-time, the light as emitted from interior 
illuminators is reflected indoors by the slats so that the difference in 
the luminance between the light-reflecting parts and the other parts in 
the slats becomes too large, whereby the surfaces of the slats 
disadvantageously glitter to give an unpleasant feeling to residents. This 
is an inconvenient problem. On the contrary to this, during daytime, the 
sun light positively reflects on the slats because of the sun 
light-reflecting layer thereof and the thus reflected light would give a 
glittering light and an unpleasant feeling to passersby and residents in 
other buildings. This is another problem. 
SUMMARY OF THE INVENTION 
One object of the present invention is to provide a sunshade which does not 
impart a dazzling or the like unpleasant feeling to residents in the 
nighttime. 
Another object of the present invention is to provide a sunshade which may 
absorb glow and heat near windows in a summer time and which may elevate a 
room-heating effect in a winter time. 
Still another object of the present invention is to provide a sunshade 
which may reduce impartation of a dazzling or the like unpleasant feeling 
to outdoor passersby and residents in other buildings. 
In order to attain the said objects, there is provided by the present 
invention a blind composed of a transparent substrate, an infrared 
ray-reflecting layer capable of reflecting an infrared ray, which is 
provided on the substrate, a sun light-reflecting layer capable of 
reflecting a sun radiant energy with partly transmitting visible rays 
therethrough, which is also provided on the substrate, and diffusive means 
capable of diffusively reflecting the light as reflected by the infrared 
ray-reflecting layer and sun light-reflecting layer, which is provided on 
at least one of the substrate, infrared ray-reflecting layer and sun 
light-reflecting layer. 
The other objects of the present invention will be obvious from the 
embodiments of the present invention which are explained in detail 
hereinafter and will be set forth in the claims attached hereto. Other 
numerous advantages of the present invention, which are not mentioned 
herein, will be apparent to those skilled in the art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A first embodiment of the present invention will be explained hereunder 
with reference to FIGS. 1 and 2. A substrate 2 of a blind slat material 1 
is made of a transparent synthetic resin such as a polycarbonate resin or 
an acrylic resin, or a transparent glass or the like. One surface of the 
substrate 2, which faces indoors, is coated with an infrared 
ray-reflecting layer 3, and the other surface with a sun light-reflecting 
layer 4. These reflecting layers 3 and 4 will be explained. The infrared 
ray-reflecting layer 3 is processed on one surface of a first base 5 made 
of a transparent resin film. This has a function of reflecting at least 
50% or more infrared rays having an infrared ray wavelength range of from 
5 to 40 .mu.m, and this may transmit visible rays. The first base 5 is 
adhered to the substrate 2 via an adhesive layer 6, and this has the 
infrared ray-reflecting layer 3 on the opposite side. The outer surface of 
the infrared ray-reflecting layer 3 is coated with a transparent 
protective layer 7. 
As the transparent and filmy first base 5, films of organic compounds, for 
example, polyolefins such as polyethylene or polypropylene; aromatic 
polyesters such as polyethylene terephthalate or polyethylene naphthalate; 
polycarbonates; vinyl halides such as vinyl chloride, vinylidene chloride 
or vinylidene fluoride; polyamides such as nylon 6 or nylon 66, etc. may 
be used, and in particular, a biaxially stretched film of polyethylene 
terephthalate is preferred. 
The protective layer 7 may be made of anyone selected from acrylic resins 
such as polymethyl methacrylate, silicone resins such as polymers obtained 
from ethyl silicate, acrylonitrile resins such as polyacrylonitrile or 
polymethacrylonitrile, as well as polypropylene, polyester resins, 
melamine resins, urethane resins, silicon oxide, magnesium fluoride, etc. 
The protective layer 7 is formed, for example, by laminating a film of the 
above-mentioned material on the infrared ray-reflecting layer 3 via an 
adhesive or by coating a solution of the above-mentioned material as 
dissolved in a solvent on the infrared ray-reflecting layer 3. 
As shown in FIG. 2, a surface 8 of the protective layer 7 is made rough by 
sand blast treatment. The rough surface 8 is made to have a density of 
such degree that the outdoor view can be seen through the slat material 1. 
Accordingly, the protective layer 7 has a function that the light as 
penetrated through the infrared ray-reflecting layer 3 and the light as 
reflected by the infrared ray-reflecting layer 3 are diffused by n the 
rough surface 8. 
The sun light-reflecting layer 4 is an aluminium layer as coated on one 
surface of a second base 9 by vacuum evaporation plating, and the second 
base 9 may be made of the same material as the above-mentioned first base 
5. The layer 4 may reflect 30% or more sun radiant energy having a 
wavelength falling within the range of from 0.4 to 2.1 .mu.m and may 
transmit 50% or less visible rays having a wavelength of from 0.38 to 0.78 
.mu.m. The second base 9 is thus processed to have the sun 
light-reflecting layer 4, on the inside thereof, and the layer 4 is 
adhered to the substrate 2 via the adhesive layer 10. 
In a blind composed of the slat materials 1 having the above-mentioned 
constitution, since each slat material 1 has the infrared ray-reflecting 
layer 3 and the sun light-reflecting layer 4 as adhered to the transparent 
substrate 2, the thermal absorption of the slats may be prevented because 
of the sun radiant energy-reflecting capacity of the sun light-reflecting 
layer 4 and the indoor heat radiation may be minimized because of the 
infrared ray-reflecting capacity of the infrared ray-reflecting layer 3 so 
that the glow and heat near windows in a summer time may be applied to a 
curtain 91, a window 93, an exterior louver 94, 95, a roof 98, a penthouse 
roof, lighting top lights, a sun roof, a transparent slate, etc. capacity 
of the infrared ray-reflecting layer 3 with properly controlling the 
transmission of visible rays therethrough because of the visible 
ray-transmitting capacity of the sun light-reflecting layer 4 so that 
these are effective for elevating a room-heating effect. 
In a night time while the outdoor area is darker than the indoor area, if 
the blind is completely shut with setting the infrared ray-reflecting 
layer 3 of all the slat materials 1 thereof to be in the indoor side, the 
light as emitted from interior illuminators is reflected by the infrared 
ray-reflecting layer 3 and the sun light-reflecting layer 4, while the 
light as reflected by these layers 3 and 4 could be diffusively reflected 
because of the rough surface 8 of the protective layer 7. Accordingly, the 
images of the interior illuminators are not mirrored or reflected Sharply 
on the slat materials 1, and the residents in the room with the blind 
would not have any dazzling or the like unpleasant feeling. 
In the above-mentioned embodiment, the slat material 1 is composed of the 
substrate 2 both surfaces of which have been coated with the infrared 
ray-reflecting layer 3 and the sun light-reflecting layer 4 individually, 
and the protective layer 7 which covers the infrared ray-reflecting layer 
3 has been processed to have the rough surface 8. In addition, the slat 
material may be composed of other various modifications of the respective 
reflective layers, as mentioned below. 
(A) FIG. 3 is referred to. A first base 15 is processed to have a rough 
surface 18, and the rough surface 18 of the first base 15 is coated with 
an infrared ray-reflecting layer 13. The layer 13 is processed to have a 
rough surface. In this case, since the degree of the roughness of the 
rough surface 18 is larger than that of the film thickness of the infrared 
ray-reflecting layer 13, the surface of the reflecting layer 13 as formed 
on the rough surface 18 may be accordingly rough. 
(B) FIG. 4 is referred to. The surface of a second base (29) on which a sun 
light-reflecting layer 24 is provided is processed to have a rough surface 
28, and the surface of a second base 29 is coated with the sun 
light-reflecting layer 24, so that the surface of the reflecting layer 24 
is made rough. 
(C) FIG. 5 is referred to. Both the surface of the protective layer 7 as 
coated on the infrared ray-reflecting layer 3 and the surface of a second 
base 39 as coated on the sun light-reflecting layer 4 are processed each 
to have a rough surface 38. Because of such constitution, the light as 
reflected by the both reflecting layers 3 and 4 may diffusively reflected 
so that the dazzling by the blind slats may be prevented in both the 
outdoor area and the indoor area. In particular, when the slat materials 1 
are set nearly horizontally with the sun light-reflecting layer 4 being 
above the substrate, the image formation of the reflected light on a 
ceiling by the sun light-reflecting layer 4 may be prevented so that the 
indoor environment for living may be improved. 
(D) An emulsion is incorporated in the formation of the substrate 2. 
Namely, the light as penetrating through the substrate 2 may be 
diffusively reflected because of the fine emulsion grains in the substrate 
2. 
In addition, the present invention includes still another modification as 
shown in FIG. 6. More precisely, a thin metal film layer 11 having both 
the capacity of the above-mentioned infrared ray-reflecting layer 3 and 
the capacity of the above-mentioned sun light-reflecting layer 4 is 
provided on one surface of the substrate, and a protective layer 47 as 
provided to coat the thin metal film layer 11 is processed to have a rough 
surface 48. Because of such constitution, the same effect as mentioned 
above can be attained. 
The thin metal film layer 11 is made of any one of gold, silver, copper, 
aluminium, nickel, palladium and tin, or an alloy of these metals, and in 
particular, it is preferably made of gold, silver, copper or an alloy 
thereof. The alloy herein referred to may contain conventional inevitable 
impurities. The thickness of the metal layer is from 30 .ANG. to 600 
.ANG., preferably from 50 .ANG. to 300 .ANG.. For formation of the thin 
metal film layer 11 any one of vacuum evaporation plating method, cathode 
sputtering method, plasma melt-spraying method, gaseous plating method, 
chemical plating method, electric plating method and combination thereof 
can be employed. In addition, the thin metal film layer 11 may be formed 
directly on the substrate 2. 
The thin metal film layer 11 thus formed may reflect 30% or more sun 
radiant energy having a wavelength range of from 0.4 to 2.1 .mu.m and may 
reflect 50% or more infrared rays having a wavelength range of from 5 to 
15 .mu.m and additionally may transmit 50% or less visible rays having a 
wavelength range of from 0.38 to 0.78 .mu.m. 
For instance, when the thin metal film layer 11 is made of silver in the 
embodiment of the slat material of FIG. 6, the slat material has 
properties as shown by the curves A, B and C in FIGS. 7(a) to 7(c). 
Specifically, the curve A shows the reflectivity of the sun radiant 
energy, which means that the slat material may reflect 30% or more sun 
radiant energy when this has the metal having a thickness of 60 .ANG. or 
more. The curve B shows the reflectivity of infrared rays, which means 
that the slat material may reflect 80% or more infrared rays when this has 
the metal layer having a thickness of 40 .ANG. or more. The curve C shows 
the transmittance of visible rays when this has the metal layer having a 
thickness of 130 .ANG. or more. Accordingly, if the metal film layer 11 is 
made of a thin silver film having a film thickness of 130 .ANG. or more, 
the reflectivity of both the sun radiant energy and the infrared rays and 
the transmittance of the visible rays may be made higher or lower, 
respectively, than the desired values mentioned above. 
Next, a second embodiment of the present invention will be explained 
hereunder with reference to FIG. 8. 
In a blind slat material 51, one surface of substrate 52 is coated with a 
first base 55 via an adhesive layer 59, and the base 55 is coated with an 
infrared ray-reflecting layer 53. The other surface of the substrate 52 is 
coated with a second base 56 via the adhesive layer 59, and a sun 
light-reflecting layer 54 is interposed between the base 56 and the 
adhesive layer 59. The infrared ray-reflecting layer 53 is coated with a 
protective layer 57. The slat material 51 of the second embodiment is 
different from the slat material 1 of the above-mentioned first 
embodiment, in that a light-diffusing agent 58 has been incorporated into 
the second base 56 and the protective layer 57 so that the light as 
reflected by the infrared ray-reflecting layer 53 and/or the sun 
light-reflecting layer 54 may be diffused by the light-diffusing agent 58. 
The surface of the protective layer 57 is not roughened. As the material 
of the first and the second bases 55, 56 is preferred a biaxially 
stretched polyethylene terephthalate film because of the high thermal 
stability and dimension stability and of the easiness of the incorporation 
of the light-diffusing agent 58 thereinto, like the above-mentioned first 
embodiment. 
As the light-diffusing agent 58, for example, can be used powders of 
inorganic substances such as kaolin, clay, CaCo.sub.3, TiO.sub.2, 
SiO.sub.2 sol or the like, or powders of organic substances such as 
thermosetting polyimide resins, etc. The light-diffusing agent 58 for use 
in the present invention may be any others than the above-mentioned 
substances, provided that these may be incorporated into the second base 
56 or the protective layer 57 without substantially lowering the strength 
of the physical properties thereof. 
The light-diffusing agent 58 may have an apparent grain size of from 0.01 
.mu.m to 50 .mu.m, and the shape thereof is not specifically limited. For 
incorporation of the light-diffusing agent 58 into the base 56 and/or the 
layer 57, for example, the following methods can be employed. 
(a) The light-diffusing agent 58 is blended into a melted synthetic resin, 
and the resin mixture is filmed to form the second base 56 or the 
protective layer 57. 
(b) The light-diffusing agent 58 is blended into a melted synthetic resin 
and the resin mixture is filmed. The resulting film is laminated to form 
the second base 56 or the protective layer 57. 
(c) The light-diffusing agent 58 is dispersed into a solution of a 
synthetic resin as dissolved in a solvent, and the resulting dispersion is 
coated on a resin film to be used as the second base 56 or the protective 
layer 57. The thus formed resin sheet is laminated to form the base 56 or 
the protective layer 57. 
(d) The light-diffusing agent 58 is dispersed in a solution of a synthetic 
resin as dissolved in a solvent, the resin being same as the material of 
the second base 56 of the protective layer 57, and the resulting 
dispersion is directly coated on the second base 56 or the protective 
layer 57. 
The amount of the light-diffusing agent 58 to be incorporated into the slat 
material 51 may be represented by the ratio of the amount of the 
diffusively transmitted light to the amount of the total transmitted light 
in the light as penetrating through the slat material 51. This is 
mentioned in JIS T8147, 6.3.7 as "surface abrasion resistance". This is 
generally designated as "cloudiness or turbidity", and the definition 
thereof is just same as the definition referred to in JIS T8147, 6.3.7. In 
order to keep the degree of the light diffusion favorable the cloudiness 
of the slat material 51 is made to be from 5% to 80%, preferably from 10% 
to 70%, whereby the light diffusion can be attained without interfering 
with the visible field. 
The blind composed of the slat materials 51 of the second embodiment may 
display the following effects, like the blind of the above-mentioned first 
embodiment. 
In a nighttime while the outdoor area is darker than the indoor area, if 
the blind is completely shut with setting the infrared ray-reflecting 
layer 3 of the slat materials 1 thereof to be in the indoor side, the 
light as emitted from interior illuminators is reflected by the infrared 
ray-reflecting layer 53 and the sun light-reflecting layer 54, while the 
light as reflected by these layers 53 and 54 could be diffusively 
reflected because of the light-diffusing agent 58 as incorporated into the 
base 56 and the protective layer 57. Accordingly, the images of the 
interior illuminators are not mirrored or reflected sharply in the slat 
materials 51, and the residents in the room with the blind would not have 
any dazzling or the like unpleasant feeling. On the contrary to this, 
during day time, the sun light could diffusively reflect on the slat 
materials 51 because of the light-diffusing agent 58 as incorporated 
thereinto so that the impartation of a glittering light and an unpleasant 
feeling to passersby and residents in other buildings could be reduced. In 
the above-mentioned second embodiment, the light-diffusing 
agent-incorporated layer has been provided on both the indoor-facing 
surface and the outdoor-facing surface of the substrate. However, even 
when the layer is provided on one surface of the substrate, the same 
effect can also be attained. 
In the above-mentioned second embodiment, the slat material 51 is composed 
of the substrate 52 both surfaces of which have been coated with the 
infrared ray-reflecting layer 53 and the sun light-reflecting layer 54 
individually, and the protective layer 57 which covers the infrared 
ray-reflecting layer 53 and the second base 56 for the sun 
light-reflecting layer 54 contain the light-diffusing agent 58 so as to 
obtain the light-diffusing effect. In addition, the slat material of the 
present invention may be composed of other various modifications as 
mentioned below. 
(A) FIG. 9(a), FIG. 9(b) and FIG. 9(c) are referred to. A light-diffusing 
agent 68 is further incorporated in either or both a first base 65 for 
forming the infrared ray-reflecting layer 53 or/and a transparent 
substrate 62, in addition to the second base 56 for forming the sun 
light-reflecting layer 54 and the protective layer 57. 
(B) FIG. 10(a) to FIG. 10(g) are referred to. A second base 76 is adhered 
to the substrate 52, and a sun light-reflecting layer 74 is coated over a 
base 76. The sun light-reflecting layer 74 is overcoated by a protective 
layer 77. The light-diffusing agents 58 and 78 are incorporated in 
accordance with various combinations of the substrates 52 and 62, the 
first and second bases 55, 65, 56 an 76, and the both side protective 
layers 57 and 77. 
In addition, the present invention includes still another modification as 
shown in FIG. 11(a) and FIG. 11(b). More precisely, a thin metal film 
layer 81 having both the capacity of the above-mentioned infrared 
ray-reflecting layer 53 and the capacity of the above-mentioned sun 
light-reflecting layer 54 is provided on both surfaces of the substrate 
52, and a light-diffusing agent 88 is incorporated into a protective layer 
87 as provided to coat the thin metal film layer 81. Because of such 
constitution, the same effect as mentioned above can be attained. 
The materials of the thin metal film layer 81 and the formation of the same 
layer 81 may be same as those of the thin metal film layer 11 in the 
above-mentioned first embodiment. If the thin metal film layer 81 is 
formed directly on the substrate 52, it is a matter of course that the 
protective layer 87 is formed on the surface of the thin metal film layer 
81 and the light-diffusing agent 88 is incorporated into the protective 
layer 87. The thin metal film layer 81 may also have the same capacity as 
the thin metal film layer 11 used in the above-mentioned first embodiment. 
The present invention is not limited to be applied to only the 
above-mentioned slat materials but may also be applied to curtain clothes, 
roll blind clothes, exterior louvers, pent roofs, lighting top lights, sun 
roofs, transparent roofs, transparent slates, window glasses, etc. In 
addition, the substrate for use in the present invention is not limited to 
be only a transparent one but any other colored visible ray-transmitting 
substrates or partly opaque substrates with patterns may also be used in 
the present invention. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and the scope thereof Accordingly, the present 
invention is not restricted by any specific embodiments thereof, only the 
limitations specifically set forth in the claims.