Abstract:
A method and apparatus for one-way graphics using a projector that projects an image onto a screen, wherein the screen is comprised of a non-transparent material, and the screen contains voids sufficient in size and distribution to allow clarity of vision when viewed through from the side opposite the projection, and wherein the area of the screen substantially reflects the projected image so that on observer viewing the screen from the projection side of the screen sees the image that is projected onto the screen. The apparatus and method may further comprise a light-absorbing layer on the back of the screen, wherein the voids in the screen extend through the light-absorbing layer. The one-way screen may include additional transparent layers for mounting and adhesion.

Description:
[0001]    This invention relates to materials and methods for one-way graphics involving projected images. This application claims benefit under 35 U.S.C. §120 of the filing date for application No. 61/656,681 filed Jun. 7, 2012. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    One-way graphic materials are materials that have an image on one side, yet permit vision through the material from the other side. Optical properties are manipulated such that the material appears opaque from the image side, but appears substantially transparent when viewed from the non-image side. Generally, one-way graphic materials are light permeable, with one relatively dark side and one relatively light side. Images are typically placed on the light side of the one-way material. People viewing from that side will see the image. People viewing the material from the back side of the material do not see the image, but instead see the environment on the far side of the one-way graphic. Other forms of one-way graphics use transparent inks and/or retroreflective materials, and rely on differences in illumination and scale perception to create the same effect, with the image typically visible from the brighter, outdoor side of the window, while being substantially invisible from the darker, inner side of the window. 
         [0003]    One-way graphics typically use expensive perforated substrates, upon which an image is printed using digital printers or silk screening. These substrates are typically films of vinyl or acryclic polymers. Other methods of production of one-way graphics involve the application of “print patterns” of bonding material onto the surface of a transparent, non-bonding substrate, as in U.S. Pat. No. 6,267,052 (Hill et al.). Images may then be printed onto the “print pattern” of bonding material to create an image layer. One-way graphics can thus be made using non-perforated films (e.g., 3M™ Scotchcal™ Clear View Graphic Film IJ8150), wherein a print pattern simulating a perforated surface is used to create unprinted surfaces that simulate the effect of perforation. 
         [0004]    All of the embodiments described above involve one-way graphic displays in which a single, permanent image is bonded to the surface of the one-way display. Because the one-way displays in use are entirely dye-based, they require the user to remove and replace a display each time the user wishes to display a different graphic image. Furthermore, existing technology for one-way graphic displays is entirely static, and does not allow for any movement of the image on the one-way graphic display. Thus, the prior art fails to take advantage of many of the advantages associated with motion pictures, television, and other video arts based on projection of images, where a single projection panel can be used to display many different types of images, and can portray motion. 
         [0005]    Similarly, although perforated screens are known in the visual arts, these generally involve screens with very small and or infrequent perforations, such that the screens are non-transparent under any circumstances. These are intended to allow sound to travel from the rear portion of the screen outward through the front of the screen. They are not suitable for use in window displays or any other types of display where the user desires the screen to be essentially transparent when the user is viewing outward from behind the screen. 
         [0006]    Accordingly, it is the object of the invention to provide screens that (1) are suitable for use in commercial and retail window displays, (2) allow easy introduction of new images without complete replacement of the one-way vision panel, and (3) allow the user to display moving images. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention relates to the use of one-way vision panels as projection screens and related apparatuses therefore. In one embodiment of the invention, an image can be projected onto a one way surface used as a projection screen. The screen comprises a panel with a non-reflective surface on one side and a light colored surface on the opposite side. The projection screen is perforated or otherwise made light permeable to enable vision through the screen. Printing a black or light absorbing pattern on a transparent sheet, and then printing a white or light reflecting coating on top of the light absorbing layer is another method of producing a projection one way screen. The projection side of the screen would have a pattern of light reflective material and voids in the pattern through which one can see. The opposite side would show a dark, light absorbing pattern with voids through which one can see. 
         [0008]    Other variations of the invention are possible, for example, a one-way projection screen panel may be constructed as a flexible sheet that can be attached to a window by use of an adhesive or electrostatic attraction. A one way projection screen can also be produced by the application of the light reflecting and the light absorbing layers directly onto the glass surface. Such layers can be printed, painted, applied by transfer, cured by heat or ultraviolet light, fused to the surface by heat, or other such means. The invention also includes various structures and methods for projecting images onto one-way screens for optimal effect, such as structures in which the projector is situated high above the average eye level of an observer, or is situated in a compartment and reflected off a mirror onto the projection screen. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0009]      FIGS. 1 and 2  show side cut-away views of alternate configurations of one-way projection screens, wherein the light-reflective portions of the one-way projection screen are placed on different sides of a transparent substrate.  FIG. 1A  is a side view of a configuration wherein the light-reflective layer is adjacent to the transparent substrate and placed on the inner (right) side of a transparent surface.  FIG. 1B  shows a similar configuration, wherein the light-reflective layer is on the outer (left) surface, with a light-absorbing layer between it and the transparent substrate.  FIG. 2A and 2B  show analogous structures with the light reflective or light absorbing layers attached directly to the transparent material. 
           [0010]      FIG. 3  shows two side cut-away views of configurations for the placement of a projector in relation to the one-way projection screen for the embodiments of  FIG. 1A and 1B . 
           [0011]      FIG. 4A  shows the placement of the projector for the configuration of  2 A.  FIG. 4B  shows the projector projecting an image onto the assembly of  2 B. 
           [0012]      FIG. 5  shows a projector arrangement where a projector directly projects an image onto a one-way projection screen. 
           [0013]      FIG. 6  shows an alternate method and apparatus for projecting an image onto a one-way projection screen from a location above and behind the projection screen through use of a mirror. 
           [0014]      FIG. 7  is an additional side-view showing use of the invention in a retail environment with the projection camera mounted to a strut above and behind the projection screen. 
           [0015]      FIG. 8  shows a projector in use with a one-way projection screen, with lines depicting the line of light travelling through the screen. 
           [0016]      FIG. 9  shows an alternate embodiment using a tinted material bonded to a semi-transparent material ( 25 ). 
           [0017]      FIG. 10  shows a structure incorporating the invention within a retail environment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    As used herein, “one-way graphic materials” and “one-way projection screens” refers to materials that appear essentially opaque and non-transparent from the image side, but appear substantially transparent when viewed from the non-image side under appropriate light conditions. The direction of one-way vision may change with environmental conditions. Images are typically placed on the light side of the one-way material. People viewing from that side will see the image. People viewing the material from the back side of the material do not see the image, but instead see the environment on the far side of the one-way graphic. Generally, one-way graphic materials are constructed using films or sheets that have multiple gaps or perforations in their non-transparent surface, thereby allowing light to permeate through the material. 
         [0019]    “Perforation” or “void” refers generally to any void or area of complete transparency in a panel of one-way graphic material or a one-way projection screen. A perforation may be physical, as in the case of a hole cut through or from a material, or visual, as in the case where a physically non-perforated substrate contains areas of transparency. Perforations may be of varying sizes or patterns, including holes, dots, grids, matrices, lattices, or random patterns. 
         [0020]    The invention includes an apparatus and method for projecting an image onto a surface having one-way vision properties. In one embodiment, a panel with a black or dark surface on one side has a light colored surface that can have embedded light reflective components on the opposite side. This assembly is light permeable so that light and vision passes selectively through the assembly. Printing a black or light absorbing pattern on a transparent sheet, and then printing a white or light reflecting coating on top of the light absorbing layer is one method of producing a projection one way screen. The screen would show a pattern of light reflective material on one side of the screen and voids in the pattern through which one can see. The opposite side would show a dark, light absorbing pattern with voids through which one can see. 
         [0021]    Alternately, the light reflective coating can be printed first which is then overlaid with a dark layer of printing. The substrate material can be various different materials that have a clear adhesive layer on the backside that is protected by a release layer. The release layer is peeled away from the substrate to expose the adhesive layer prior to the installation of the one way projection screen to the glass surface. The substrate may also be a material with static cling properties; materials with an embedded electrostatic charge that is attracted to the window or glass surface through electrostatic attraction. 
         [0022]    A one way projection screen can also be produced by the application of the light reflecting and the light absorbing layers directly onto the glass surface. Such layers can be printed, painted, applied by transfer, cured by heat or ultraviolet light, fused to the surface by heat, or other such means. 
         [0023]    The one-way projection screen may be constructed of a variety of materials known to those of skill in the art, including materials such as glass, vinyl, calendared PVC, ceramic, plastic compounds, composite materials, or the like. Appropriate commercially available starting materials upon which additional layers could be added to produce a one-way projection screen suitable for the invention include PVC films such as SuperVue™, ImageVue™, and ImageJetVue™ films distributed by Clear Focus Imaging, Inc., and Avery® HP MPI 2728 perforated 65/35 film. 
         [0024]    Additionally, portions of a one way graphic display or a one way projection screen display may be backed with a light absorbing adhesive coating, or a light absorbing coating that is backed with either a transparent, translucent or a light absorbing adhesive. The portions of the one-way graphic display or a one-way projection screen display with the adhesive are adhered to a transparent substrate in a way that leaves voids on the transparent substrate. The transparent substrate may be such materials as glass, vinyl, ceramic, plastic compounds, composite materials, or the like. 
         [0025]    This transparent substrate may be coated with an adhesive for adhesion to another transparent substrate such as a window, wind screen, wind break, door, glass unit, plastic unit or the like. The adhesive used could also include such means of adhesion as adhesives, glues, epoxy compound(s), mucilage, cements, static cling or the like. This adhesive may also be protected by means of a removable membrane or cover. Alternately, the adhesive may be applied to either the graphic assembly or the second transparent substrate, namely the window, wind screen, wind break, door, glass unit, plastic unit or the like. 
         [0026]      FIG. 1  shows the application of a one-way projections screen applied to a transparent surface. This one-way projection screen is constructed of a transparent substrate ( 5 ), to which is applied a light reflective material and a light absorbing material. This assembly is then adhered to a transparent material. This transparent material can be glass or plastic commonly known as a window ( 17 ). In  FIG. 1A  this construction is as follows from left to right, first is the transparent material ( 17 ), second is the transparent substrate ( 5 ), third is the light reflective material or image material ( 3 ),  4 th is the light absorbing material ( 2 ).  FIG. 1B  from left to right shows the light reflective material or image ( 3 ), a light absorbing material ( 2 ), a transparent substrate ( 5 ), and a transparent material ( 17 ). In both  1 A and  1 B, the light absorbing and the light reflective materials have voids that allow the passage of light and vision. 
         [0027]    In  FIG. 2  the light absorbing ( 3 ) and the light reflective materials ( 2 ) are bonded directly to the transparent material ( 17 ).  FIG. 2A  shows the light reflective material bonded to the transparent material and backed by the light absorbing material.  FIG. 2B . shows the light absorbing material bonded to the transparent material and backed by the light reflective material. 
         [0028]    The portions of the one way graphic display or a one way projection screen display may be in many different shapes, sizes, patterns and configurations. They may be produced through such well known means as cutting, slitting, molding, die cutting, kiss cutting, or cutting by laser, water jet, or any other method of cutting materials that may apply. 
         [0029]    Common patterns of perforation for one-way vision panels known to those of skill in the art include 1.5 mm holes removing 35-50% of the printable (i.e., image-forming) surface of the panel. Also known are panels in which 2.0 mm holes remove 50% of the printable surface. Other appropriate patterns of perforation will be known to those of skill in the art. 
         [0030]    Those of skill in the art will recognize that interactions between the pattern frequency associated with the image projection and the pattern frequency of the screen perforation (whether physical perforation or merely visual perforation of a visually non-perforate sheet) can produce interference or moire effects, and will pair the projector and projection screen appropriately to avoid these effects if desired (e.g., choosing a projector with a pixilation pattern that is significantly different from the perforation pattern of the projection screen). 
         [0031]    Woven or nonwoven materials may be used as the substrate for one way vision materials. These materials could be made of thermo-plastic or thermosetting threads of filaments. Both the nonwoven and the woven configurations would be created in such a way that a sufficient open area is created. The woven or nonwoven mesh could be pressed flat, which would aid in the application of an adhesive layer and in the installation of the material to another surface. Pressing the material flat would eliminate the variation of thickness of the warp and weave of the woven material, which also would aid in the printing process. The pressing could be done any number of ways including using combinations of heat and pressure. This could include passing the material through heated rollers that would flatten and bond the individual filaments. 
         [0032]    The woven or nonwoven material could be coated with an adhesive material either before or after the flattening process and this adhesive in turn could be protected by a removable protective cover. The side opposite the adhesive and protective layer could have images printed, painted or otherwise formed upon it in order to create a one way graphic material. Additionally, woven or nonwoven filaments could be pressed into three dimensional shapes creating one way vision masks or graphic displays with three dimensional elements. 
         [0033]    Each or all of the one way graphic mediums in this briefing can be laminated with a clear protective covering to protect the reflective or the light absorbing surface. The use of an ultraviolet protective laminate would protect the screen from deterioration or fading from exposure to ultraviolet radiation. Additionally, the screen is protected from damage during cleaning operations. 
         [0034]    The image can be projected onto the light reflective coating through such means as movie, slide, computer, TV, Closed Circuit TV, VCR, DVD, videodisk or the like. The projector can be mounted on the side of the one way screen with the light reflective coating or it can be mounted on the side of the graphic with the light absorbing coating. When it is mounted on the side of the screen with the light absorbing coating the image can be projected through a window or void and then reflected onto the screen by use of mirrors or prisms. This configuration would be beneficial in an application where an image is projected onto one way screens mounted on windows of a retail storefront. In this application, the projector and other hardware can remain safely inside the store, while only mirrors or prisms are on the other side of the wall. 
         [0035]      FIG. 3  shows the placement of a projecting device ( 18 ) that projects through the transparent material ( 3 ) to the light reflective material. The projected image is viewed from the same side as the projector.  FIG. 3A  shows the material of  1 A in use.  FIG. 3B  shows the placement of the projector for the configuration of  1 B. The image is viewed from the same side as the projector. 
         [0036]      FIG. 4A  shows the placement of the projector for the configuration of  FIG. 2A . The projected image goes through the transparent material and has reflected by the light reflective material. The image is viewed from the same side of the assembly as the projector or the left side of the assembly of  FIG. 4A .  FIG. 4B  shows the projector projecting an image onto the assembly of  FIG. 2B . the projected image is reflected off of the light reflecting coating and is viewed on the same side of the assembly as the projector. 
         [0037]      FIG. 5  shows up projector arrangement where the projector ( 18 ) directly projects an image onto a one-way projection screen. 
         [0038]      FIG. 6  shows an image projected ( 19 ) from a projector ( 18 ) and reflected onto a one-way projection screen. Mirrors, prisms or other such reflective devices ( 20 ) may be used to reflect the image as desired. 
         [0039]      FIG. 7  shows a cut away side view of the front of a retail environment using an embodiment of the invention. A projector ( 18 ) is mounted to the inside wall of the building in front of a projection port or small window ( 17 ). An image is projected through this projection port ( 17 ), onto a reflective panel ( 20 ), and reflected onto the front windows of the business ( 21 ). The front windows are covered with a one-way projection screen that reflects the image to people outside of the building. The reflector ( 20 ) may be incorporated into an awning design so that its true purpose may be disguised. 
         [0040]      FIG. 8  shows that, with the placement of the projector ( 18 ) and/or the reflector ( 20 ) high enough, the light from the projector ( 19 ) does not get in the eyes of an observer ( 22 ) on the opposite side of the one way projection screen. A bright projection light shining through the one-way vision screen therefore does not hamper the observer&#39;s view through the assembly ( 23 ). 
         [0041]    It is also possible to project an image from the back onto a one way graphic screen. The screen would consist of a tinted material or coating covering a transparent material that diffuses the light. This assembly has holes or voids in the pattern so that light can be transmitted through the assembly. When an image is projected onto the screen it is projected through the tinted material to the translucent material that diffuses the image. The projected image is visible on the side of the one way projection display opposite the projector, while the image is not visible from the side where the projector is. This effect is similar to that of a person wearing sunglasses. The sunlight goes through the glasses and is visible from the opposite side (that of the wearer) but is not as noticeable from someone on the sunny side. While this configuration would have benefits from the placement of the projector inside the building, a more powerful or brighter projector would be needed to compensate for the loss of image brightness to the tinted material. 
         [0042]    This rear projection one way graphic material can be constructed in a number of different ways. For example it could consist of a sandwich of tinted material and light diffusion material that is perforated, cut, slit, or otherwise made with holes or voids for the passage of light. Or it could be made of light diffusion material and tinted material that is printed, painted, sputtered, deposited, bonded transferred to or otherwise placed upon a backing material which is positioned in proximity to a window or other opening. Additionally it could be printed, painted, sputtered, deposited, bonded, transferred to or otherwise placed directly on glass, plastic, or other transparent materials. 
         [0043]      FIG. 9  shows a tinted material ( 24 ) bonded to a semi-transparent material ( 25 ). This assembly is attached to a window or similar surface ( 17 ). A projector ( 18 ) projects an image ( 19 ) onto the assembly. The projected image is transmitted through the tinted material ( 24 ) to the semi-transparent or diffusing material ( 25 ) where the light from the image is diffused. The image is visible on the left side of the assembly but not as much from the right. Although not shown, the assembly may be bonded to a transparent structure that is then placed upon the window surface. Additionally the one way rear projection screen may be configured for either interior or exterior applications. As with other configurations described in this briefing both the tinted material and the semi-transparent material may be chosen from the group consisting of paints, inks, compounds, membranes, films, panels, coatings, or the like. 
         [0044]    Each and all of the graphic materials described in this document can be free standing, part of a building or similar structure, a fence or similar divider, a wall, a shell, a skin, part of a vehicle, or any other place where either glass, transparent plastic, windows, signage, graphic displays, billboards, fleet graphics, bus wraps, direction signs, corporate ID graphics, printed materials, painted materials or the like are used. The products described herein may be constructed so that the projection surface is three dimensional rather than flat. Additionally, the one way graphic material could be perforated or punctured so that when installed upon a transparent surface trapped air bubbles are easily removed. 
         [0045]    One-way projection technology can create a dynamic presence for retail stores. In addition to slide shows, multimedia and video presentations, this invention can use real time animation and project it onto one-way graphics on storefronts. Imagine walking along a wall and a cartoon character or a company mascot starts walking along side you and starts talking to you. This character then asks you what you are looking for and walks you into the store. The character can walk into posts (not looking where it is going) and other funny and interesting effects. The action could be live, controlled by an actor, or it could be programmed and activated by motion detectors. 
         [0046]    A storefront in a retail mall or strip mall environment could be designed to maximize the effectiveness of this medium for luring customers into the store. One such design would be where the walls are shaped in a shallow “V” with the open doors at the base of the “V”. The projected image moves ever closer to the center of the “V”, and the open doors, luring the customer along with it. When the character gets to the doorway, the image moves into the store, hopefully bringing the customer along with it. The image can originate at both ends and work towards the opening at the center either simultaneously or alternately. 
         [0047]    Projecting the image onto a one way material with a high ratio of open area such as a mesh or gauze type of material can create eerie ghost-like effects where the image appears to be semi-transparent. Changing the level of the backlighting can intensify this effect. 
         [0048]    Sophisticated sound systems can project the sounds so that they seem to come from the characters that are projected onto the screen. These speakers can be placed so that the sound comes from different areas around the glass area, or they can be placed so that the sound reflects off of the glass where the action is occurring. Alternately, magnets and coils may be embedded into or bonded to the glass so that the entire surface of the glass vibrates, becoming in effect one large speaker. 
         [0049]      FIG. 10  shows the front of a building in which the front wall of the building consists of the configuration of  FIG. 3A ,  3 B,  4 A,  4 B, or  5 - 9 , which includes one-way projection screen covered windows ( 27 ), a projection system, and an optional reflective assembly. In  FIG. 10  the front of the building is in the shape of a shallow “V,” with the entrance to the front of the building at the apex of the “V” ( 28 ). Just inside the entrance, a cash point, display, or other structure ( 29 ) is shown which also has one-way projection screens and a projected image.  FIG. 10  shows the possibility of using the graphics to lure customers in a retail environment to the entrance of the store through the use of the dynamic and innovative graphics projected onto the front of the glass storefront, and then into the store with additional graphics projected onto the walls inside the store.