Abstract:
A projection system for making an object appear and disappear to an observer on cue is disclosed. The system remotely activates a reflective axis and a transmissive axis within a polarized window for making an object on cue appear and disappear. In one aspect, this system contains a reflective back plate, a polarized window, and a textured surface. A reflective back plate is placed behind an object. A polarized window is placed in front of the object. A textured surface is placed in front of the polarized window. A polarized light source is placed in front of the textured surface. If the polarized light is aligned parallel to a reflective axis, the textured surface is visible to an observer. If the polarized light is aligned parallel to the transmissive axis, the textured surface and the object are visible to an observer.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. Provisional Application No. 60/481,012 entitled “POLARIZED LIGHT VALVE” filed on Jun. 23, 2003 and is related to U.S. Provisional Application No. 60/481,013 entitled “POLARIZED APPEARING AND DISAPPEARING OBJECT SYSTEM” filed on Jun. 23, 2003. The above-referenced applications&#39; contents are incorporated by reference herein in their entirety. 
     
    
     BACKGROUND  
       [0002]     1. Field  
         [0003]     This disclosure relates to making an object appear hidden or visible to an observer.  
         [0004]     2. General Background  
         [0005]     Special effects designers may be required to make an object appear hidden (disappear) or visible (appear) to an observer on cue. For example, an amusement park having a haunted mansion may desire to make an object, such as a ghost, mysteriously appear and as just as mysteriously disappear to an observer. One conventional approach involves a projection system having an electromechanical means for directing light at and redirecting light from an object. However, this approach may not to an observer make an object disappear or reappear because such electromechanical means requires a finite time for turning on and turning off a light source illuminating the object. Furthermore, this approach may not smoothly nor in a controllable manner transition from hidden to visible an object to an observer on cue.  
         [0006]     Thus, there is a need for an improved process for making an object appear hidden or visible to an observer and provide other advantages over presently available projection systems.  
       SUMMARY  
       [0007]     An improved optical system as disclosed herein uses optical polarizers wherein changing the relative orientation of the optical polarizers provides for an image of an object to appear and to disappear from behind a surface. For example, the optical system may be a projection system wherein an object appears visible, or disappears and becomes invisible to an observer.  
         [0008]     In one aspect, the projection system is a thin film system. A reflective back plate is placed behind an object. A polarized window is placed in front of the object. The polarized window is a thin film surface having a reflective axis and a transmissive axis. The transmissive axis transmits light that vibrates in the same plane as the transmissive axis. The reflective axis reflects light that vibrates in the same plane as the reflective axis. The textured surface, for example, is a semi-transparent surface. The polarized window is for example a thin film surface. The textured surface is placed in front of the polarized window. A light source placed in front of the textured surface is adapted to polarize light transmitted toward the textured surface. The light source remotely activates the projection system by changing the light polarization. Depending on the polarization of the light source, the object may be made invisible or visible to an observer.  
         [0009]     In one aspect, the polarization of the light source is oriented parallel to the reflective axis. In this aspect, the light passes through the textured surface and is reflected by the polarized window, preventing viewing of the object. In another aspect, the polarization of the light source is oriented parallel to the transmissive axis. In this aspect, the light passes through the textured surface and the polarized window displays a visible object and the textured surface.  
         [0010]     In another embodiment, the polarization of the light source is transitioned from parallel to the transmissive axis to parallel to the reflective axis. The effect is to create an optical cross fade of the object from a visible state to an invisible state. In one aspect, the transition involves two states for appearance (visibility) to disappearance (invisibility) of the object to an observer. In the alternative, the transition is gradual involving multiple states from the appearance of an object (visible), through partial visibility of the object, to the disappearance (invisibility) of the object to an observer. The effect of having multiple states allows the appearance and the disappearance of the object to slowly fade from one state to another state. The polarizing window may be thin film material applied directly to a wall. Therefore, the disappearance and appearance of the object to an observer is created in a very small real estate area.  
         [0011]     For instance, special effects design engineers for studios or movie houses may utilize this improved optical system for creating disappearing and appearing image of an object, such as ghost. Some other applications of this system include convenience stores, point of sales displays, train stations, or other locations where an image of an object is periodically displayed on a remotely located wall or other surface. In yet another example, the application of a polarized light source, such as a flashlight, to an object produces a real image of the object appearing in corners or crevices of a room and other random remote locations. This creates the effect of a scary environment for haunted house attendees.  
         [0012]     The foregoing and other objects, features, and advantages of the present disclosure will be become apparent from a reading of the following detailed description of exemplary embodiments thereof, which illustrate the features and advantages of the disclosure in conjunction with references to the accompanying drawing Figures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIGS. 1A and 1B  illustrate one embodiment where an object is hidden from an observer.  
         [0014]      FIGS. 2A and 2B  illustrate one embodiment where an object is visible to an observer.  
     
    
     DETAILED DESCRIPTION  
       [0015]     The present disclosure involves using a polarized light projector and polarization materials that have different orthogonal polarization characteristics in order to make an object hidden (disappear) or visible (appear) to an observer on cue. Through this disclosure, an observer is only exemplary in nature and may be replaced by a video camera, recording device, screen, or the like.  
         [0016]      FIGS. 1A and 1B  illustrate one embodiment where an object is invisible (hidden) to an observer. This optical system includes source polarizer  40 , textured window  30 , a polarized window  20 , and an object  10 . In one aspect, object  10  may consist of a thin film material deposited on a clear acetate material. In one aspect, the thin film material may a clear acetate material deposited with images such as a cartoon character, a text message, or characters. The thin film material occupies a very small real estate area so it can be incorporated in small real estate area. In another aspect, object  10  may be, for example, a 3-dimensional object such as a figurine.  
         [0017]     Textured surface  30  is a semi-transparent surface. For example, textured surface  30  is a clear acetate material deposited with, for example, a thin film material like brick surface  35 .  
         [0018]     Polarized window  20  is dual polarized window having both a reflective axis  25  and a transmissive axis  35  to light. In one example, polarized window  20  is a light polarizing film Diffuse Reflective Polarizing Film (DRPF) from manufacturer 3M.  
         [0019]     Source polarizer  40  includes a first transmissive axis  45  which transmits light vibrating in the same plane as transmissive axis  45 . Light aligned along first transmissive axis  45  passes through source polarizer  40 . In one aspect, source polarizer  40  is a light polarizing material such as Moxtek, aluminum deposited on glass, or an organic polarizer such as Hn-38 manufactured by the 3M Company.  
         [0020]     Light source  50  is an illumination source such as an ETC Source Four with 750 watts illumination power or the like.  
         [0021]     In this system, object  10  is placed behind polarized window  20 . Textured surface  30  is placed in front of source polarizer  40 . Light from light source  50  illuminates source polarizer  40 . Source polarizer  40  has a first transmissive axis  45  aligned with reflective axis  35  of polarized window  20 . Source polarizer  40  passes light aligned along first transmissive axis  45  toward textured surface  30 . Light passes through textured surface  30  to polarized window  20 . Light aligned with reflective axis  35  of polarized window  20  is reflected back toward textured surface  30 . An observer sees an illuminated textured surface  30 , as shown for example in  FIG. 1B , with brick elements  35 .  
         [0022]      FIG. 2A  illustrates one embodiment where an object is made visible to an observer. In this aspect, light source  50  transmits light to source polarizer  40 . Light aligned along transmissive axis  45  of source polarizer  40  travels through textured surface  30 . Light transmitted by textured surface  30  that aligns with transmissive axis  25  of polarized window  20  travels to object  10 . Object  10  transmits light to back plate  60 .  
         [0023]     Back plate  60  is a polarization-maintaining surface. For example, back plate  60  may be plexiglass or acrylic material such as made by manufacturer Autoglass or the like. In another example, back plate  60  is deposited with a reflective material such as Krylon 1401 silver paint.  
         [0024]     Light from back plate  60  traveling through object  10 . Object  10  is illuminated. Object  10  passes light to polarized window  20 . Light aligned along transmissive axis  25  of polarized window  20  is transmitted to textured surface  30 . Textured surface  30  is illuminated. An observer sees textured surface  30  plus visible image of object  10  as shown in  FIG. 2B .  
         [0025]     In one alternative, the polarization of the light source may be slowly transitioned from parallel to the transmissive axis to parallel to the reflective axis. This effect provides for a user to create optical cross fade of the object to an observer from a visible state to an invisible state.  
         [0026]     For example, as source polarizer  40  is rotated clockwise, object  10  visibility changes from a visible state to an invisible state. In another example, source polarizer  40  rotates either clockwise or counter clockwise direction providing to an observer an object&#39;s visibility that cyclically changes from a visible state, through numerous partially visible states, a nearly visible state, and to a visible state.  
         [0027]     In one aspect, the transition is done in a user-controlled manner. The transition involves two states for appearance (visibility) to disappearance (invisibility) of the object to an observer. In the alternative, the transition is gradual, involving multiple states from the appearance of an object (visible), through partial visibility of the object, to the disappearance (invisibility) of the object to an observer. Multiple states allow an observer to see an object slowly fade from one state to another state. Polarizing window  40  may be thin film material applied directly to a wall. Therefore, the disappearance and appearance of the object to an observer can be created in a very small real estate area.  
         [0028]     In one aspect, the background remains the same color as the visibility of the object transitions from a visible state to an invisible state. For example, polarized window  40  is a Diffuse Reflective Polarizing Film (DRPF) from the 3M Company. In this example, the background remains white as object  10  transitions from the visible state to the invisible state. In another aspect, polarized window  40  is the Dual Brightness Enhancement Film (DBEF) from the manufacturer 3M. In this aspect, the background remains silver as object  10  transitions from the visible state to the invisible state.  
         [0029]     In another aspect, textured surface  30  can be any transparent substance. In this aspect the visual surface of the system is the polarized window as previously discussed.  
         [0030]     In another aspect, textured surface  30  may be a theatrical scrim. For example, the theatrical scrim is a material having a wide weave with part of the material being at least partially transparent to light. In this aspect, as source polarizer  40  is rotated while directed at the theatrical scrim, the hidden object transitions from a nearly invisible state to, for example, a nearly full visible state.  
         [0031]     In yet another aspect, the surface of the theatrical scrim may contain a printed image. In one example, the printed image is a face. In this example, object  10  is a skull. By illuminating the printed image with light source  50  using source polarizer  40  parallel to transmissive axis  25  of polarized window  20 , the skull is visible to an observer. Alternatively, changing the polarization of source polarizer  40  parallel to reflective axis  35  of the polarized window  20 , the skull is invisible to an observer. In the invisible state, the observer sees the printed image of the face. In the visible state, the observer sees a composite image of the printed face and the skull.  
         [0032]     In another alternative, textured surface  30  may be a partial mirror. The partial mirror transmits a percentage of incident light while reflecting another percentage of incident light. For example, the partial mirror may be a DBEF. In this alternative, as source polarizer  40  is rotated while pointed at the partial mirror causes object  10  transitioning from a nearly invisible state to a nearly fully visible state. In this aspect, the partial mirror is a DBEF.  
         [0033]     In another alternative, light source  50  may be replaced with a hand held flashlight with source polarizer  40  that is fixed in position. In this aspect, light source  50  is a portable device that may be repositioned by an observer. This aspect allows the observer to interact with the object. Thereby, the observer can actively cause the object to appear or disappear. In another aspect, source polarizer  50  may be located on the hand held flashlight is allowed to freely rotate.  
         [0034]     In yet another alternative, light source  50  can be replaced with a video projector. For example, the video projector may project a single light color for illuminating object  10 . In yet another aspect, textured surface  30  may be a projected image from a video projector. In the alternative, the projected image is provided by the video projector is one or more moving images.  
         [0035]     Information as herein shown and described in detail is fully capable of attaining the above-described object of the disclosure and the present embodiments of the disclosure, and is, thus, representative of the subject matter, which is broadly contemplated by the disclosure. The scope of the disclosure fully encompasses other embodiments which may become obvious to those skilled in the art, and is to be limited, accordingly, by nothing other than the appended claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described embodiment and additional embodiments that are known to those of ordinary skill in the art are hereby expressly incorporated by reference and are intended to be encompassed by the present claims.  
         [0036]     Moreover, no requirement exists for a device or method to address each and every problem sought to be resolved by the disclosure, for such to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. However, one skilled in the art should recognize that various changes and modifications in form and material details may be made without departing from the spirit and scope of the inventiveness as set forth in the appended claims. No claim herein is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”