Abstract:
A window with modifiable transparency, the window including window panes that define at least one cavity in between the panes. The window also including one or more mechanisms for introducing and removing a transparency modifying fluid into and from said one or more cavity.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to systems controlling light and heat passage through a transparent medium, such as a window, door, or partition and the like. 
       BACKGROUND OF THE INVENTION 
       [0002]    The past few decades have seen widespread use of multilayer window glass panes to meet growing demands for air-tight, thermally insulated houses. Performance multilayer glass panes are typically used for the purpose of increasing thermal insulation. In order to provide privacy clear (transparent) glass may be made matte or translucent using high pressure sanding methods or chemical etching techniques. Liquid crystal display (LCD) panel systems and methods may be used to achieve translucent glass at will (e.g., at the push of a button). 
         [0003]    These active systems require electric circuitry to provide energy to the system to modify the properties of an internal material within the system, and the optical properties of the whole system. These systems further typically require sophisticated production methods and equipment, resulting in a final product that is expensive to produce, install, and use. In addition, these systems may be subject to size limitations, e.g., they cannot be produced above a certain size, and the size has to be predetermined during production and cannot be modified by the installer at the customer site. 
         [0004]    To save energy costs windows may reduce the light and heat energy passing through to an interior. In some embodiments, heat reflecting glass panels, e.g., panels that include one or more layers of a metal oxide, a metal, and a metal nitride on a transparent glass sheet, may reduce air-conditioning system loads. These heat reflecting glass panels may be effective in reducing air-conditioning system load through good sunlight shielding performance (e.g. triple silver layer low emissivity film structure). However, light shielding and transmission is constant—unaffected by the outside conditions and the customer&#39;s will. 
         [0005]    Photochromatic materials may also reduce incoming light intensity; e.g., the use of silver halide materials within a medium of glass. Typically, when sunlight hits the silver halide crystals, it generates metallic silver from the silver ions, and turns the crystals from a transparent medium to black, effectively darkening the glass in the process. This process is reversible. Photochromatic systems are typically expensive to produce and typically do not allow modification of light intensity by the consumer: light itself activates the process and the medium darkens proportionally to the amount of light energy illuminating it. 
       SUMMARY OF THE INVENTION 
       [0006]    It is therefore an object of the present invention to provide a window with modifiable transparency. 
         [0007]    The window may allow control and modification of light and heat properties in a medium such as a partition, window or a door. To allow alteration of light properties, at will, from a clear transparent medium, through which the image of the scenery through the medium is clearly visible, to, for example, a translucent medium where the light from the image is scattered such that the image cannot be clearly seen, or, in another example, to a reduced transmission of the light (or heat or other radiation) passing through. 
         [0008]    Some embodiments of the invention may include a window with modifiable transparency. The window may include window panes, the panes defining at least one cavity in between the panes. 
         [0009]    The window may further include one or more mechanisms for introducing and/or removing a transparency modifying fluid into and from said one or more cavity. 
         [0010]    In some embodiments of the invention, the transparency modifying fluid may be opaque. 
         [0011]    In some embodiments of the invention, the transparency modifying fluid may be translucent. 
         [0012]    In some embodiments of the invention, the transparency modifying fluid may be reflective. 
         [0013]    In some embodiments of the invention, the transparency modifying fluid may be nontransparent. 
         [0014]    In some embodiments of the invention, the transparency modifying fluid may be in a compressed state. 
         [0015]    In some embodiments of the invention, the window may also include a pump mechanism for introducing and removing a transparency modifying fluid into and from or more cavities. 
         [0016]    In some embodiments of the invention, at least one cavity is at least partially reflective to radiation in a selected spectral region. 
         [0017]    In some embodiments of the invention, at least one cavity contains a fluid that is different than a fluid contained in at least another one of a plurality of cavities. 
         [0018]    In some embodiments of the invention, the window panes may be arranged parallel to one another. 
         [0019]    In some embodiments of the invention, the window panes may be arranged non-parallel to one another. 
         [0020]    In some embodiments of the invention, the at least one cavity has one or more walls, the walls may include a transparent material selected from the group of transparent materials consisting of glass, polymer, Polyester, resin, and air. 
         [0021]    In some embodiments of the invention, at least one of the transparency modifying fluid may be spectrally selectively transmissive to light or heat. 
         [0022]    In some embodiments of the invention, the window may include a seal. 
         [0023]    In some embodiments of the invention, the seal may include a sealing material selected from the group of sealing materials consisting of: glue, rubber, latex, resin, silicone, polymer, and nylon. 
         [0024]    In some embodiments of the invention, the transparency modifying fluid in at least one of the cavities may be translucent, and the transparency modifying fluid of another cavity may be opaque. 
         [0025]    In some embodiments of the invention, at least two cavities may be filled such that their optical properties are substantially identical to one another. 
         [0026]    In some embodiments of the invention, at least two cavities may be filled such that their optical properties are substantially non-identical to one another. 
         [0027]    In some embodiments of the invention there may be a pattern within the cavity allowing for different fluids to be distributed within the cavity. 
         [0028]    In some embodiments of the invention the transparency modifying fluid may be configured to affect and control heat transmission, absorption or reflection. 
         [0029]    In some embodiments of the invention, the transparency modifying fluid may be in gaseous state. 
         [0030]    In some embodiments of the invention, the window may include a floater. 
         [0031]    In some embodiments of the invention, the window may include one or a plurality of reservoirs to contain the transparency modifying fluid. 
         [0032]    In some embodiments of the invention, the window may include a control unit for introducing and removing the transparency modifying fluid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as embodiments only and in no way limit the scope of the invention. Like components are denoted by like reference numerals. 
           [0034]      FIG. 1  depicts a schematic illustration of two glass panes of a window with modifiable transparency according to an embodiment of the present invention. The window may include spacers in between the glass panes that may provide the sealing of the interior volume; 
           [0035]      FIG. 2  depicts a schematic illustration of a sealed volume, e.g., a cavity, within a window with modifiable transparency, according to an embodiment of the invention; 
           [0036]      FIG. 3  depicts a schematic illustration of two reservoirs of dark and/or opaque ink configured to allow for the passage of the ink through a pump into a cavity in a window with modifiable transparency, according to an embodiment of the invention; 
           [0037]      FIG. 4  depicts a schematic illustration of a window with modifiable transparency in a translucent state, according to an embodiment of the invention; 
           [0038]      FIG. 5  depicts a schematic illustration of a window with modifiable transparency configured to selectively reflect incident radiation, according to an embodiment of the invention; 
           [0039]      FIG. 6  depicts a schematic illustration of a window with modifiable transparency configured to fully reflect incident radiation, according to an embodiment of the invention; and, 
           [0040]      FIG. 7  depicts a schematic illustration of a window with modifiable transparency with an additional ink reservoir, according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0041]    In some embodiments, a system for controlling light and heat in a partition, door or a window (hereinafter, window), according to embodiments of the present invention may include multiple transparent layers coupled to form a window. Transparent layers may be transparent to one or a plurality of forms of radiant energy including light and/or heat. Transparent layers typically have a property related to the transparency to radiant energy. Typically, such system may include between 2 and 6, or more transparent layers. 
         [0042]    In some embodiments, the window may have two larger, and in some examples, dominant, layers forming a window pane-like appearance and providing for an interior. In some embodiments, the window may include other layers, the other layers may be configured to connect and seal the interior part of the two dominant layers. 
         [0043]    In some embodiments, two dominant layers are the only layers in the window, forming a window pane-like appearance, and those layers may be configured to connect and seal the whole interior box, and in some examples, a cavity within. 
         [0044]      FIG. 1  depicts a schematic illustration of two glass panes of a window with modifiable transparency according to an embodiment of the present invention. The window may include spacers in between the glass panes that may provide the sealing of the interior volume. 
         [0045]    The schematic illustration indicates one or a plurality of layers of parallel placed transparent glass, e.g., window panes. The window panes within a window, configured to modify the characteristics of the light and heat passing through the window, according to an embodiment of the present invention with spaces and sealers in the window. 
         [0046]    In some embodiments, window  10  may be an exterior or interior window of a structure. In some embodiments, window  10  may form a partition within the interior of the building, such as a cubicle in an office. In some embodiments, window  10  may be used as a partition wall, for example, between a conference room and a corridor. In some embodiments, window  10  may be configured to be used as a door. In some embodiments, window  10  may be used as a skylight pane or a shop window or another window. 
         [0047]    Window  10  may be used in sunglasses, crash helmets, or car windows, where the window may be curved, arched wavy, and/or otherwise not flat. In some embodiments, an activation of the transparent properties of window  10  may be made by a user, manually, by a controller, control unit, or by using a remote control or by one or a plurality of heat and/or light sensors activating one or a plurality of pumps, as described below. 
         [0048]    Light transmission, typically light transmission into a structure such as a home, commercial, industrial or other structures may be modified by window  10 . Window  10  may be configurable to have variable transparency properties, the variable transparency properties including reflectivity, opacity, absorbency and other properties. 
         [0049]    Window  10  may include at least two window panes  20 , the window panes typically glass, plastic or other transparent material. Window  10  may include a sealing frame  30 , the sealing frame configured to encompass the perimeter of window  10  and provide for a sealed volume in one or a plurality of cavities  40  between window panes  20 . Cavity  40  may have width W. Window  10  may have a frame  15 . 
         [0050]    Typically, light and heat, and other forms of radiation may pass through a window. Light and heat radiation may pass through, via light and heat transmission, when window  10  is transparent. In some embodiments, when window  10  is transparent, it is transparent to at least part of the visible spectrum, e.g. window  10  may include spectrally selectively transmissive materials such as tinted or colored transparent materials. 
         [0051]    Cavity  40  between the glass panes  20  may be temporally, selectively, partially, and/or wholly filled with a fluid, e.g., where the fluid may be a liquid or a gas  50  that may render the window nontransparent or partially transparent. In some embodiments, when window  10  is nontransparent it may be opaque (i.e., typically reflecting or absorbing parts of the electromagnetic spectrum) to a region of the electromagnetic spectrum which the transparent region may otherwise typically transmit. Window  10  may be translucent or partially translucent (matte, textured, or scattering) to a region of the electromagnetic spectrum which the transparent region may otherwise typically transmits. 
         [0052]    Typically, window  10  may be made nontransparent by the incorporation of materials into one or more cavities  40  such as a fluid, e.g., a liquid and/or gas. These materials may include, but are not limited to an etched transparent material, a polymer, a painted transparent material, ink deposited on a transparent material, a lamination layer, a metal, and a deposited metal layer, dyes pigments, inks, and chemicals that affect various part of the electromagnetic spectrum. Liquid or gas  50  may be colored gases that can absorb or reflect sections of the electromagnetic spectrum. 
         [0053]    In some embodiments, when window  10  is nontransparent, window  10  may be reflective to all or some of the visible and/or heat spectrum. Typically, materials may be put into or added to cavity  40  to affect the transparent and nontransparent nature of window  10 , modifying the transmission properties of window  10 . 
         [0054]    In some embodiments, cavity  40  may include a fluid, e.g., liquid or gas  50  that may alter the refractive index of window  10 , or have absorption in part of all of the visible spectrum, or in the heat spectrum. The light absorption of the materials may be modified, in some instances, by varying the concentration of the light absorbing substances incorporated into the liquid or gas, such as dyes, pigments, or other materials. 
         [0055]    In some embodiments, concentration and other parameters of liquid or gas  50  in cavity  40  can be chosen by a user or someone else to affect, in addition to their light absorption, scattering and reflection, also the viscosity, boiling and freezing points, adhesion to glass, surface tension, and other physical parameters that may affect the liquid or gas  50 . 
         [0056]    In some embodiments, a first cavity  40  may be filled with a liquid or gas  50  and/or other materials, and a second cavity  40  may be filled with a liquid or gas  50  and/or other materials such that the two filled cavities have optical properties that are the same or substantially similar to each other. In some embodiments the cavities may be wholly or partially overlapping within window  10 . In some embodiments the cavities may be non-overlapping within window  10 . 
         [0057]    In some embodiments, one cavity  40  may be filled with a liquid or gas  50  and/or other materials, and a second cavity  40  may be filled with a liquid or gas  50  and/or other materials such that the two filled cavities have optical properties that are different and/or substantially dissimilar to each other. In some instances, the optical properties may include the absorption or reflection of the region of the electromagnetic spectrum, or in the state of the material within the cavity, the viscosity of the material within the cavity or other measures of similarities or differences. 
         [0058]    In some embodiments frame  30  may encompass glass panes  20  with a seal. The seal may be tight or in some instances, airtight. In some embodiments cavity  40  in window  10  may typically be from 0.1 to 50 mm wide where the width of the cavity may be indicated by W in the schematic illustration. 
         [0059]      FIG. 2  depicts a schematic illustration of a sealed volume, e.g., a cavity, within a window with modifiable transparency, according to an embodiment of the invention. 
         [0060]    The schematic illustration depicting one or a plurality of glass panes within a window frame, the window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above in  FIG. 1 . 
         [0061]    In some embodiments, liquid or gas  50  may be introduced and/or removed from cavity  40  via pipes  60  and/or pipes  130 , typically via a pumping action as the result of one or more pumps  70 , e.g. an electric pump or other pump mechanism. In some embodiments other methods and apparatuses may be employed to move liquid or gas into and or out of cavity  40  including, for example, pipes, a magnet, an electromagnet, an electric motor, a piezoelectric motor, a bimetallic strip, and a spring, as are known in the art for use in a pump, typically a manual or electric pump. Typically, pipes  60  direct the liquid or gas  50  to one or a plurality of parts of one or a plurality of cavities  40 . 
         [0062]    Liquid or gas  50  may be directed to a bottom portion  80  of window  10  such that liquid or gas  50  rises from bottom portion  80  when liquid or gas  50  fills up cavity  40 . Liquid or gas  50  may also exit cavity  40  via the same pipes  60  and pump  70 , back into a reservoir  90 . Reservoir  90  may be located within frame  30 , described above, of window  10 . 
         [0063]    Pump  70  may be a manual pump and may be operated by squeezing a flexible reservoir, e.g., reservoir  120 , the flexible reservoir containing liquid or gas  50 . In some embodiments, pump  70  may be designed to be able to pump in and out of window cavity  40  one or more types of liquid or gas  50  sequentially, i.e., pump in one liquid or gas  50 , than pump it out, and then pump in another liquid or gas  50 . In some embodiments, multiple pumps  70  may be used, each pump  70  pumping one type of liquid or gas  50 . In some embodiments, a pump  70  may be configured to contain a cleaning fluid, or other fluid to clean window  10  internally between panes  20 , so as to clean and clear the window of potential obstructions to viewing. 
         [0064]    Liquid or gas  50  may be kept, maintained, held, or otherwise found within a reservoir, e.g., reservoir  90 , the reservoir being located, for example, near pump  70 , and in some embodiments, instead of pump  70 . Liquid or gas  50 , when located in the reservoir may be in a compressed state and/or form and configured to be released in the appropriate amount to render the required change in the window transmission. 
         [0065]    In some embodiments, glass panes  20  may be made, or coated with material that wholly or partially repels an optically modifying material, e.g., the dark liquid or gas or the transparent and/or translucent liquid or gas so as to not allow the optically modifying material to stick to cavity walls, e.g., dominant layers forming a window pane  20 , of cavity  40 . 
         [0066]    In some embodiments, a hydrophobic coating on the interior side of one or more glass panes  20  may wholly or partially repel a water based liquid or gas and prevent the water based liquid or gas from sticking to the sides of glass panes  20 , or other material. 
         [0067]    An interior of cavity  40  may be filled with a reflective liquid or gas. Typically, the reflective liquid or gas can be an intrinsic reflective material, such as mercury, or other liquid or gas in which reflective material can be incorporated to wholly or partially reflect the incoming light. In some embodiments, the reflective material to be incorporated into the liquid or gas may be solids that can reflect light such as gallium, mercury, and/or other metal compounds, glass bids, glass powder, titanium dioxide, mica, or other materials. 
         [0068]    In some embodiments, reflective material to be incorporated into the reflective liquid or gas may be a chemical substances that dissolve in the liquid or gas to render it wholly or partially reflective, such as suspension of iron and/or silver nanoparticles in ethylene glycol Typically, the reflective liquid or gas may have a visible light and heat reflectance ranging from 10% to 100%, e.g., from 70% to 100%. 
         [0069]    Cavity  40  may be empty, e.g., may be a vacuum or empty of gas or liquid  50 , or may be filled with colorless transparent liquid or gas, configured to provide a clear view of the image beyond window  10 . 
         [0070]    Window  10  may be filled with the translucent liquid or gas, providing for light to enter a room interior from the outside, but not a clear image of the outside or a clear image of the inside. Typically, window  10  may be filled with the translucent liquid or gas such that it is configured to provide privacy. 
         [0071]    In some embodiments, window  10  may be filled with reflective liquid or gas, configured to provide for light and heat to reflect back to the building exterior and configured to limit the amount of light and heat from entering a building or room interior from the outside. Typically, window  10  may be filled with the reflective liquid or gas such that it is configured to provide privacy shading, and cooling. 
         [0072]    In some embodiments, window  10  may be filled with a reflective liquid or gas  50 , configured to provide for light and heat to reflect back to the building or room interior and configured to limit the amount of light and or heat from leaving the building or room interior to the building exterior. 
         [0073]    The colors of a transparent liquid or gas  50  and of the translucent liquid or gas  50  may be the same or similar. In some embodiments, the colors may be dissimilar. Typically, the transparent or translucent liquid or gas  50  may be of any color depending on the materials that are incorporated into the liquid or gas  50 , such as dyes, pigments or the basic color of the intrinsic liquid or gas. In some embodiments, the color of a reflecting liquid or gas  50  may be modified by incorporating dyes and pigments. 
         [0074]    In some embodiments, a reflective liquid or gas  50  may be pumped into window  10  when the window is placed in areas that face the sun so that it may reflect, rather than absorb, the incoming energy, reducing the heat load on building interiors. 
         [0075]    Typically, a floater  140  on the top surface of liquid or gas  50  (typically liquid) may be configured to reduce evaporation, to affect surface tension of the liquid, and/or to enhance the uniformity of the liquid or gas rising from the bottom of cavity  40  and in some instances, may be incorporated into the window cavity. Floater  140  may be of any buoyant material. When liquid or gas  50  is removed from cavity  40 , floater  140  may remain at the bottom of the window, typically in a recess  150 , the recess configured such that the floater remains out of sight, not obscuring the window view. 
         [0076]      FIG. 3  depicts a schematic illustration of two reservoirs of dark and/or opaque ink configured to allow for the passage of the ink through a pump into a cavity in a window with modifiable transparency, according to an embodiment of the invention. 
         [0077]    The window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above. 
         [0078]    The schematic illustration of a pumping system to introduce and/or remove a liquid or gas in and/or out of the window cavity. The pumping system may introduce and remove, or carry out either the introduction or the removal of a liquid or gas, e.g., a fluid into one or more cavities within the window, the window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above. 
         [0079]    In some embodiments, light does not pass through the window cavity and, typically, both heat and light may be absorbed by window  10 . 
         [0080]    Reservoir  90  may contain a gas or fluid to be pumped in to cavity  40  via pump  70 . There may be a second reservoir  120 . In some embodiments, there may be a plurality of reservoirs  90 . Typically, pump  70  pumps liquid or gas  50  from reservoir  90  through pipes  60  into cavity  40 . Reservoir  90  and  120  share pipes  60 . In some instances reservoir  90  may be connected to pipes  60  and reservoir  120  may be connected to pipes  130 . 
         [0081]    In some embodiments, pump  70  may be a motor or similar device. There may be a plurality of pumps  70 . In some instances, content within reservoir  90  and content within reservoir  120  may be pumped into cavity  40  by the same pump. In some embodiments, content within reservoir  90  and content within reservoir  120  may be pumped into cavity  40  by separate pumps. 
         [0082]    As described below, a nontransparent material configured to be pumped into cavity  40  may be opaque or may block a significant amount of light. In some embodiments, transparent areas may be more transmissive of light than nontransparent (translucent or opaque) areas, but not necessarily transparent in the sense of a scene being readily viewable in an undistorted manner via the transparent areas. 
         [0083]      FIG. 4  depicts a schematic illustration of a window with modifiable transparency in a translucent state, according to an embodiment of the invention. 
         [0084]    The schematic illustration of a window that may turn from transparent to translucent, according to an embodiment of the invention. The window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above. 
         [0085]    In  FIG. 4  the cavity may change the optical and/or other characteristics of the window, or a portion thereof from transparent to translucent, according to an embodiment of the invention. 
         [0086]    Window  10  may include a transparent sheet  100 . Typically, transparent sheet  100  may be a transparent medium such as glass that is transparent or semitransparent in the visible light wavelength range, or, in some embodiments, a resin sheet, in some embodiments, a synthetic resin sheet, that is transparent or semitransparent in a visible light wavelength range. Other similar materials may also be used. 
         [0087]    Typically, transparent sheet  100  may be made of float glass, soda-lime glass, borosilicate glass, crystallized glass, or other glass or similar materials. The resin sheet may be made of, for example, PET (polyethylene terephthalate), PVB (polyvinyl butyral), EVA (ethylene-vinyl acetate copolymer), or a cellulose resin. 
         [0088]    Transparent sheet  100  may have a thickness ranging from 0.0001 to 50 mm, e.g., from 0.1 to 10 mm. Other dimensions may be used. Transparent sheet  100  may be an optically active substrate, e.g., a light polarizing material, a laminate of micro lenses, or ventricular system. Transparent sheet  100  may be capable of transferring image-forming light, mainly unaffected in some embodiments. Transparent sheet  100  may typically have a visible light transmittance ranging from 10% to 100%, e.g., from 70% to 100%. Transparent sheet  100  may include an add-on transparent medium  170  to a glass pane, e.g., glass pane  20 , such as a synthetic resin laminate. The add-on medium may also be gelatin, polymethyl methacrylate (e.g. Plexiglas®), or when the overall structure is properly supported, air (e.g., a void). 
         [0089]    Add-on transparent medium  170  may have a thickness ranging from 0 mm (absent, a clear empty window) to 10 mm, e.g., from 0 to 6 mm. Add-on transparent medium  170  may also be any non-transparent, e.g., translucent substrate that was made to be transparent in some of its areas, or was cut out of a translucent medium to make it transparent. 
         [0090]    A first glass panes  20  may be substantially identical with a second glass pane  20  in window  10 , with similar optical properties and include one or a plurality of transparent and one or a plurality of nontransparent regions. In some embodiments, the optical properties of the regions may differ from one another (e.g. differently sized areas or different spacing between areas). In some instances, the transparent and nontransparent regions in one region may be substantially identical to one another (e.g. same sized areas with identical spacing). In some embodiments, the transparent and nontransparent regions may differ from one another in size or spacing (e.g. one larger than the other). The optical properties may vary across the regions of the layer of glass panes  20 . 
         [0091]    In some embodiments, a dark liquid or gas  50 , e.g., ink or other dark liquid or gas may be pumped into cavity  40  the dark liquid or gas may fill an internal volume of cavity  40 , masking the view through window  10 . In some instances, when a dark liquid or gas  50  is pumped out of cavity  40 , window  10  will appear to be clear again, or in some embodiments, will provide a viewer with a mostly or totally unobstructed view through window  10 . 
         [0092]    In some embodiments, reservoir  90  may contain a dark liquid or gas  50  to be pumped in to cavity  40  via pump  70 . There may be a second reservoir  120  with a second liquid or gas  50 . There may be a plurality of reservoirs  90 . 
         [0093]    Typically, pump  70  pumps liquid or gas  50  from reservoir  90  through pipes  60  into cavity  40 . Reservoir  90  and  120  may, in some instances, share pipes  60 . In some embodiments, reservoir  90  may be connected to pipes  60  and reservoir  120  may be connected to pipes  130 . 
         [0094]    Pump  70  may be a motor or similar device, a more pump via a motor or a similar device. In some embodiments, there may be a plurality of pumps  70 . Content within reservoir  90  and content within reservoir  120  may be pumped into cavity  40  by the same pump. Content within reservoir  90  and content within reservoir  120  may be pumped into cavity  40  by separate pumps. 
         [0095]    In some embodiments a translucent window becoming transparent, according to an embodiment of the invention. 
         [0096]    In some embodiments, a translucent medium may be included in window  10 , e.g., a translucent sheet  160  as described and shown in  FIG. 6 . Translucent medium may be the substrate of a transparent sheet (e.g., glass), which was treated to become translucent, and may be capable of scattering the incoming image forming light, so as to scatter and diffuse the image so that it may not be clearly seen by the human eye. Translucent medium may have a visible light transmittance ranging from 10% to 100%, e.g., from 70% to 100%. Other ranges may be used. 
         [0097]    Translucent medium may be the result of a treatment of the transparent sheet into the translucent state by, for example, chemical etching or sand blasting. Translucent medium may also be, for example, a transparent substrate that was made to be translucent in some portions thereof. 
         [0098]    In some embodiments, when translucent medium or translucent substrate is included in window  10 —the translucent medium or substrate or sheet typically rendering the window translucent, using liquid or gas of similar refractive index would allow the window to become transparent when the liquid or gas is introduced into the window cavity. 
         [0099]    Translucent medium may be an add-on medium to the liquid or gas, such as a synthetic resin laminate. Translucent medium may have a thickness ranging from 0.01 mm to 10 mm, e.g., from 0.1 mm to 2 mm. Other dimensions may be used. Translucent medium may also be gelatin, Plexiglas® material, paper, polyester, photographic film, materials added by vacuum deposition, or sputtering techniques, and/or ink. 
         [0100]    Window  10  may include a translucent sheet or translucent medium or translucent substrate (not shown). Typically, translucent sheet  160  may include a translucent medium such as glass that is translucent or semi-translucent in the visible light wavelength range, or, in some embodiments, a resin sheet, in some embodiments, a synthetic resin sheet, that is translucent or semi-translucent in a visible light wavelength range. Other similar materials may also be used. 
         [0101]    Typically, translucent sheet may be made of float glass, soda-lime glass, borosilicate glass, crystallized glass, or other glass or similar materials. The resin sheet may be made of, for example, PET (polyethylene terephthalate), PVB (polyvinyl butyral), EVA (ethylene-vinyl acetate copolymer), or a cellulose resin. 
         [0102]    Translucent sheet  160  may have a thickness ranging from 0.0001 to 50 mm, e.g., from 0.1 to 10 mm. Other dimensions may be used. Translucent sheet  160  may be an optically active substrate, e.g., a light polarizing material, a laminate of micro lenses, or ventricular system. Translucent sheet  160  may affect image forming light and may not allow an image, or in some embodiments a recognizable image, to be perceived through the window. However, when rendering translucent sheet  160  transparent, translucent sheet  160  will not adversely affect the image forming light. Translucent sheet  160  may typically have a visible light transmittance ranging from 10% to 100%, e.g., from 70% to 100%. Translucent sheet  160  may include an add-on translucent medium to a glass pane, e.g., glass pane  20 , such as a synthetic resin laminate. The add-on medium may also be gelatin, polymethyl methacrylate (e.g. Plexiglas®), or when the overall structure is properly supported, air (e.g., a void). 
         [0103]    The add-on medium may have a thickness ranging from 0 mm (absent, a clear empty window) to 10 mm, e.g., from 0 to 6 mm. 
         [0104]    In this example, without the addition of liquid or gas  50  in cavity  40  the image seen through window  10  appears as a scattered image light, e.g., the discernability or clarity of the image that should be seen through window  10  is limited. 
         [0105]    When liquid or gas  50  of a similar refractive index to the translucent medium or sheet  160 , enters cavity  40 , and comes in contact with an etched glass pane  20  or other etched glass surfaces, the liquid or gas  50  may smooth the etched glass pane  20  or other etched glass surface, changing the properties of glass pane  20  from one that scatters light into one that allows parallel light to pass through and become a discernable image to a viewer. 
         [0106]    Typically window  10  is configured such that when liquid or gas  50  comes in contact with the translucent sheet, liquid or gas  50  may have limited contact, or no contact with a first side and/or facet of the translucent sheet. In some embodiments a second side of translucent sheet maybe flat and clear, e.g., not etched. 
         [0107]    In some instances, a first and second side or facet of the translucent sheet may be etched when liquid or gas  50  enters cavity  40  from a first and a second side, e.g., in a case where there are at least a first cavity  40  and a second cavity  45  in window  10 , with a common wall between the first and second cavity  40 . 
         [0108]    In some embodiments, a connecting pipe  55 , depicted schematically in the figure for illustrative purposes, may be between cavity  40  and cavity  45  and/or between additional cavities. There may be additional connecting pipes  55 . One or a plurality of connecting pipes  55  may be configured to assist in controlling the distribution of material, e.g., non-transparent material between cavity  40  and cavity  45 , or other cavities. The controlled distribution may modify the radiation energy distribution within the window 
         [0109]      FIG. 5  depicts a schematic illustration of a window with modifiable transparency configured to selectively reflect incident radiation, according to an embodiment of the invention. 
         [0110]    In some embodiments, as light passes through the window it may be scattered, providing a degree of privacy, according to an embodiment of the invention. 
         [0111]    The figure schematically shows an illustration of the translucent material filling out the cavity in the window. In some embodiments of the invention, producing an unclear image. The window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above. 
         [0112]    In some embodiments, when a transparent and/or translucent liquid or gas  50  is pumped into cavity  40  in window  10 , window  10  may become translucent, scattering the image light and producing unclear images when seen through window  10 . 
         [0113]    Light, depicted as arrow  95  and heat, depicted by arrow  85  may be partially absorbed and/or partially reflected, depending on the optical characteristics of liquid or gas  50 . 
         [0114]    In some embodiments, a translucent liquid or gas is pumped into cavity  40 . The translucent liquid or gas may be a liquid or gas in which a translucent material can be incorporated to scatter the incoming light. Translucent material to be incorporated into the liquid or gas may be solids that can scatter light such as glass bids, glass powder, titanium dioxide, mica, or other materials. 
         [0115]    In some embodiments, the translucent material to be incorporated with a liquid or gas may be chemical substances that dissolve in the liquid or gas to render it translucent, such as a substrate of a transparent sheet, which was treated to become translucent, and is capable of scattering the incoming image forming light, so as to scatter and diffuse an image so that it may not be clearly seen by the human eye. Typically, a translucent liquid or gas or a liquid or gas containing translucent material may have a visible light transmittance ranging from 10% to 100%, e.g., from 70% to 100%. 
         [0116]    The transparent and/or translucent liquid or gas may include water, alcohol, benzene, or other clear liquid or gas which is transparent or semitransparent to the visible light wavelength range. In some embodiments, the translucent liquid or gas may be Polyacrylamide (poly(2-prop-enamide)), Polyaluminum chloride (PAC), flocculants, nanometer silicon dioxide dispersion, or any other translucent liquid or gas  50 . 
         [0117]    Typically, the transparent and/or translucent liquid or gas may be capable of transferring light and/or scattering image forming light. In some embodiments, the translucent liquid or gas may have a visible light transmittance ranging from 10% to 100%, e.g., from 70% to 100%. The transparent and/or translucent medium may be an add-on medium to the base liquid or gas, such as nanometer silicon oxide. 
         [0118]      FIG. 6  depicts a schematic illustration of a window with modifiable transparency configured to fully reflect incident radiation, according to an embodiment of the invention. 
         [0119]    In some embodiments, light, UV, IR, heat and other radiation from other sources of energy may be reflected providing shading, privacy and cooling, according to an embodiment of the invention. 
         [0120]    The figure schematically illustrates an example of light and heat rays when interacting with a window filled with a translucent fluid. The window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above. 
         [0121]    There may be multiple cavities  40  created inside window  10 , such that each cavity  40  may input and output a material of modifying optical properties of light and heat, so that a combination of these materials in the different cavities  40  will have the desired optical properties of the window. For example: one cavity  40  may be filled with heat absorbing, but light transmitting material that allow for light to be transmitted to the room interior, as well as heat. 
         [0122]    In some embodiments, each or both of the applicable materials from cavities  40  that absorb heat and/or transmit light may be pumped into and out of cavities  40  by the user. In some instances, multiple cavities  40  may allow various combinations of colors or sections of the light or heat spectrum to pass through window  10 , the various combinations of colors or sections of the light or heat spectrum passing through window  10  configured to change the light and room appearance. 
         [0123]    Pump  70  may be configured to pump a material, e.g., mercury, into cavity  40 . Pump  70  may be configured to pump material into cavity  40 , such that cavity  40  reflects incoming light. A fraction of the incoming light may be reflected. In some embodiments, the reflective material, e.g., a reflective liquid or gas  50  may be made to be selectively reflective and absorbing to different regions of the incident spectrum: e.g., it may reflect the heat but absorb in the visible region of the spectrum reducing heat load but appearing colored or tinted to the human eye. 
         [0124]    In some embodiments, selective reflective and absorbing properties of liquid or gas  50  may be designed to be visibly different to a human eye depending on the location of the viewer. For example, a viewer within an interior of a structure may view a reflective liquid or gas, the reflective liquid or gas configured to be mainly reflect heat and absorb one section of the visible section, e.g. absorb magenta, as appearing green. A viewer external to the structure in which window  10  is coupled may view the reflective liquid or gas, the reflective liquid or gas configured to be mainly reflect heat and absorb a different section of the visible spectrum, e.g. absorb yellow, as appearing blue. In some embodiments, an exterior facing glass pane  20  of window  10  may be configured to reflect the heat, cooling the interior of the building, while an interior facing glass pane  20  absorbs the room heat. 
         [0125]    In some embodiments, light and heat may be selectively absorbed and/or reflected depending on the material filling cavity  40 . In some embodiments, a translucent material or sheet  160  filling cavity  40  may reflect a majority of light and a majority of heat, absorbing a minority of heat and allowing a minority of light to pass through. 
         [0126]    Translucent material may reflect a minority of light and a minority of heat, allowing a majority of the light to pass through window  10  and a majority of heat to be absorbed. Translucent material may reflect a majority of light and a minority of heat, allowing a minority of the light to pass through window  10  and a majority of heat to be absorbed. 
         [0127]    In some embodiments, translucent material may reflect a minority of light and a majority of heat, allowing a majority of the light to pass through window  10  and a minority of heat to be absorbed. Translucent material may be configured such that other combinations of heat and light reflectance and absorbance and transmittal may also occur. 
         [0128]    In some instances, an exterior facing glass pane  20  of window  10  may be configured to absorb the heat, heating the interior of the building, e.g., configured to warm the building interior, while an interior facing glass pane  20  reflects heat, back to the interior, e.g., configured to preserve heat. 
         [0129]      FIG. 7  depicts a schematic illustration of a window with modifiable transparency with an additional ink reservoir, according to an embodiment of the invention. 
         [0130]    The window as drawn, is for illustrative purposes, and may or may not be similar or the same as the window described above. 
         [0131]    The figure schematically illustrates of an example of one cavity within a window with a plurality of different reservoirs of liquid or gas materials that can absorb, scatter and reflect light and heat waves. 
         [0132]    Three reservoirs are shown in the illustration for illustrative purposes only, fewer or more reservoirs may also be used. 
         [0133]    Typically, pump  70  may be used to input and output a liquid or gas  50  into and out of cavity  40 . One or a plurality of pumps  70  may be employed. In some embodiments, each reservoir  90  may be coupled to a unique pipe  60  to transport a material, e.g., a fluid, in the reservoir into cavity  40 . 
         [0134]    In some embodiments, one or a plurality of reservoirs  90  may be filled with high optical density material. Typically, the high optical density material may be ink, laminate, pigment, and/or paint of any kind. Different materials may be superimposed in window  10 , the different materials pumped into distinct cavities  40 . 
         [0135]    In some embodiments, light, e.g., a low optical density, shading may be provided by materials that are not optically dense, the materials pumped in form a reservoir  90  into a first cavity  40 ; other cavities  40  in window  10  may have a higher optically dense material pumped in from a second reservoir  90 . When both cavities  40  are filled, in this example, the optical density of the two cavities is combined to create a higher optical density window to a wavelength, e.g., a wavelength in the visible spectrum. 
         [0136]    In some embodiments, when one cavity  40  is filled with material having a low optical density, e.g., 0.3 (transmitting 50% of the light) and a second cavity  40  is filled with a material with a higher optical density, e.g., 0.7, then window  10  transmission in this superimposed (combined) mode of the combined filled cavities is 1.0, or light transmission of about 10%. 
         [0137]    In some embodiments, one or a plurality of cavities  40  of a multi-cavity window  10  may be partially filled, so as to allow for different areas of window  10  to pass different intensities of parts of the visible and heat spectrum. An opaque liquid or gas  50  may be pumped in via pump  70  into bottom of cavity  40 , filling only a portion of the volume of a first cavity  40  and the visible area of cavity  40 , and a liquid or gas  50  is pumped in via pump  70 , or another pump, to fill an entirety or majority of a volume of a second cavity  40 . 
         [0138]    In some embodiments, when the first cavity  40  is half full and the second cavity  40  is full, a lower half of window  10  will typically be dark and cut the light intensity in the room to half, while an upper part of window  10  may allow light to pass through. Typically, the above example may be configured to provide privacy with the light coming through the top of window  10  being scattered. 
         [0139]    In some embodiments, fluid of gas  50 , including, in some instances, dense materials, may be configured to be spectrally selectively transmissive, e.g., tinted with various colors. This result in a change in color appearance of window  10  when one or a plurality of layers are moved, may allow for many possibilities of colored windows permutations. 
         [0140]    Patterns may be incorporated into cavities  40 , the patterns configured such that when changes in light characteristics occur; these changes may be viewed differently in window  10  from instances under different light characteristics. For example, when a liquid or gas  50  of a particular density fills an area, and is colored green, and a second optically dense liquid or gas  50  fills a second area, and is colored in red, one or a plurality of superimposed areas in window  10  may provide an appearance in that section that may appear to be very dark to the human eye, while the transparent areas, e.g., where optically dense fluid and or gas  50  are not filling cavity  40 , may appear bright and neutral in color to the human eye. When the optically dense colorful areas move or are moved over the transparent areas, a portion or all of window  10  may have red and green areas in close proximity, which appears to a viewer as yellow. 
         [0141]    In some embodiments, the use of reflecting material within one or more cavities  40  may prevent a high density material from heating substantially, thus eliminating or reducing a need to use double glazing to reduce heat transfer. In some embodiments, areas within window  10  containing high optical density fluids or gases may also be suitable to reflect heat energy, with reflection, in some embodiments, in the far, or thermal, infrared (IR) spectrum. In some embodiments, high optical density fluids or gases may have an optical density in the range of 0.1 to 10.0. 
         [0142]    When heat reflecting material is used, it may be suitable for heat load reduction in a building when window  10  is placed in an exterior window and door panes in a building, in skylights or other areas. To further reduce the heat load, windows  10  may include a double glazing window system, where a vacuum or other medium insulate the building interior from heat absorbed by the heat absorbing layers in window  10 . 
         [0143]    In some embodiments, areas of window  10  containing fluids or gases  50  that are transparent or nontransparent may be configured to be spectrally selectively transmissive. For example, some areas of window  10  may transmit infrared or visible radiation while absorbing, scattering, or reflecting radiation of another selected spectral region. 
         [0144]    In some embodiments, diffusing materials included in fluids or gases  50 , the fluids or gases configured to make window  10  translucent, may incorporate heat reflecting materials that may reduce the heat load on the building interiors. Typically, an additional cavity  40  of a heat reflecting filled material may be filled with a liquid or gas  50  the liquid or gas  50  configured to make the additional cavity  40  appear transparent, or semitransparent, or a selective mirror, that may reflect the heat while allowing the light to pass on to the translucent layer behind. 
         [0145]    The Width of cavity  40 , W, described above with reference to  FIG. 1  may be modified to be wider at a bottom of the window and narrower at a top of window  10 , the narrowed width W configured to allow a lesser amount of liquid or gas  50  to be in an upper portion of cavity  40 , e.g., near the top of window  10 . Typically, when there is lesser amount of liquid or gas  50  in a portion of cavity  40 , the portion with the lower volume may have a characteristic wherein it has less optical stopping power compared to another portions of window  10 . When a first portion of window  10  has less optical stopping power than a second portion, the first portion may comparably provide for a higher passage of light and heat than the second portion. 
         [0146]    Typically, when window  10  contains two portions, a first portion with comparably less optical stopping power, this may result in producing variable, gradient, in the optical properties of window  10 . 
         [0147]    In some embodiments, a variable volume of the liquid or gas  50  configured to be nontransparent can be used within the same cavity  40 , allowing variable (and, in some instances, gradual) shading by the window. For example: a narrower width W configured to provided less volume at a bottom of cavity  40 , compared to a top of cavity  40 , may allow lower transmission of optical energy of the top of the window than the bottom. This may allow window  10  to mask or shade the sun when the sun is high in the sky, while, in some embodiments, e.g., in a tall structure, allowing unobstructed (or lightly shaded) viewing of a street below. 
         [0148]    In some embodiments, one or a plurality of connecting pipes  55 , described above may be between cavity  40  and cavity  45 , cavity  45  described above, and/or between and/or connecting additional cavities. One or plurality of connecting pipes  55  may be configured to assist in controlling the distribution of material, e.g., non-transparent material between cavity  40  and cavity  45 , or other cavities. The controlled distribution may modify the radiation energy distribution within the window 
         [0149]    Windows  10  containing multiple cavities  40  may also be used to offer the user the choice of obtaining reduction in light intensity or increase in light scatter. For example, a window  10  may contain a first cavity  40  filled with a liquid or gas  50  that has high optical density and a second cavity  40  containing a liquid or gas  50  with translucent scattering properties. A user may be given a choice of filling up a first or second or another cavity  40 . Filling up the first cavity  40  may result in reducing light intensity in a room. Filling the second cavity  40  may result in increased privacy for user on the interior. 
         [0150]    A multi-cavity window may also be made using layers  170  of different material and thicknesses such as glass, Plexiglas® material, polyester films, photographic films, polyester film (e.g. Mylar® material), or polycarbonates. This may allow for less weight and thickness of a layer than if the layer were made of glass. 
         [0151]    A multi-cavity window  10  may include double glazing glass panes  20 . In some embodiments, one or a plurality of seals  180  may maintain the integrity of one or more cavities  40 . Seals  180  may be made of, for example with glue. Seals  180  may include sealing materials including rubber, latex, resin, silicone, polymer, or nylon. Seals  180  may include other materials that may be capable of providing suitable protection against the elements and being flexible enough to absorb small movements of the glass that may be as small as 0.01 mm. Seals  180  may cover the gap between the panes from an outside of a structure containing window  180 . A short distance movement of one pane over another could be accommodated by seals  180 . 
         [0152]    In some embodiments, glass panes  20 , or other materials that form an exterior wall  190  of cavity  40  may be configured to expand or contract at a different rate than a second exterior wall of cavity  40 , the expansion and/or contraction typically depending on temperature changes. In some embodiments, an exterior wall  190  may be made to move and increase a gap width W and a cavity  40  volume, by means of an apparatus (e.g., a bi-metal) that expands or contracts based on temperature. An exterior wall  190  may be made to move by means of an apparatus  200  that may be activated by light intensity (e.g., a photo detector) and/or activated by change in temperature (e.g., a heat-detector). 
         [0153]    In some embodiments, one or a plurality of cavities  40  in a multi-cavity window  10  may not be parallel to each other, may be curved, or may form repeated characteristics. 
         [0154]    An external wall  190  of cavity  40  may include areas that are cut out to make it change its optical properties. 
         [0155]    A nontransparent liquid or gas  50 , and/or a transparent liquid or gas  50  in one or a plurality of reservoirs  90  of cavities, or within a single cavity  40 , may be composed of different materials. The different materials may enable providing the window  10  cavity  40  with variable optical density, privacy, or spectral transmission and reflection options (e.g. brighter and less transmissive of heat near the top, scattering for privacy at the bottom). 
         [0156]    In a multi-cavity window  10 , an exterior facing cavity  40  may be configured to contain high optical density fluids or gases  50  which may include a reflective material, and/or high optical density fluids or gases  50  configured to reflect light and heat, and a second, interior facing cavity  40  may be configured to contain different fluids or gases  50  of a different color (and texture). In some embodiments, high optical density fluids or gases  50  within exterior facing cavity  40  may be configured to simulate a one way mirror, so the window  10  appearance may be of minor from the outside, and dimmed image of the outside scenery from the inside of the building. 
         [0157]    A multi-cavity window  10  may incorporate a dial button, switch, a lever, or electrical switch, and/or other device configured to input and output material into and out of the cavities  40 . 
         [0158]    In some embodiments, of a multi-cavity window  10 , a layer  210  may be put over and/or between the exterior walls  190  of cavity  40 . Layer  210  may be connected to exterior walls  190 , and/or configured to cover a gap between the exterior walls  190 . Layer  210  may be made of elastic material such as latex. It may be located in the areas covered by the window frame  15 . Alternatively, if such layer is made of transparent material it may completely cover the whole panes and some or all the related equipment. 
         [0159]    In some embodiments, of a multi-cavity window  10 , one or more cavities  40  may have a pattern (created by adding or subtracting ink (optically modifying material) from the cavity volume) that may not be visible to a viewer when a liquid or gas  50  is either inside or outside of cavity  40  and may be revealed to the viewer during the transition to the an other state, e.g., when cavity  40  is either filled or emptied, due to the motion of a material within cavity  40 . The pattern may be of any color, and combinations of colors can be made with patterns in different cavities in a multiple cavities system. 
         [0160]    Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. 
         [0161]    While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.