Abstract:
An interactive display that is resistant to liquid spills and vandalism. An interactive display includes a display chassis that has a chassis top support. A tamper proof and liquid resistant display surface can be attached to the chassis top support with a plurality of fasteners, so that the top is readily removable and thus, easily replaced if scratched or otherwise damaged. When attached to the display chassis, the display surface forms a continuous, gap-free top surface that prevents liquid from entering the display chassis.

Description:
BACKGROUND 
   Presently, there are a wide variety of user-interactive display systems on the market. For example, touch screen computers, commercial and consumer video games, kiosks, and automated teller machines, all utilize some form of interactive display. Additionally, other types of interactive display technologies are finding application in appliances such as microwaves, refrigerators, and even washers and dryers. Generally, interactive displays are constructed of materials having particular optical properties that are required for the specific type of display/input technology being used. 
   Since most commercial interactive display devices are operated vertically, or in a nearly vertical position, in order to maximize optical contrast, such displays are not generally configured for impact resistance or liquid spill resistance. However, in the case of a kiosk designed for installation in a public facility, such as an airport or a national park, it is quite important that the user interface surface comprising the interactive display be resistant to liquids, vandal resistant, and readily replaceable in the event of damage by users. Therefore, an interactive display that provides a durable, removable top surface having desirable optical properties, and which is also tamper resistant and not damaged by liquid spills would be of particular interest. 
   SUMMARY 
   Several implementations of an interactive display that is resistant to liquid spills and vandalism are described below in detail. In one implementation, an interactive display includes a display chassis that has a chassis top support. A tamper proof and liquid resistant display surface can be attached to the chassis top support with a plurality of fasteners, so that the top is readily removable and thus, easily replaced if scratched or otherwise damaged. When attached to the display chassis, the display surface forms a continuous, gap-free top surface that prevents liquid from entering the display chassis. 
   Another implementation described in detail below is directed to a spill and vandal resistant top for an interactive display system. The system is described as having an optically transparent top layer and a mounting frame. The top layer is described as including a shatter-resistant sheet having upper and lower surfaces with an edge surface extending between the upper and lower surfaces. The mounting frame is described in one implementation as having a bonding surface that is bonded to the lower surface of the top layer, adjacent to the edge of the top layer. A chassis attachment surface can be affixed to the support layer against the lower surface of the top layer using fasteners that are configured to mount the mounting frame to a supporting chassis of the interactive display system. A plurality of receptacles are provided in the mounting frame for fasteners so that the top layer can readily be removed and replaced if damaged, by releasing the fasteners. The upper surface of the top layer again presents a continuous, gap-free surface that prevents a spilled liquid from entering the interactive display system and resists removal and damage by vandalism. 
   A method for attaching a liquid and tamper resistant top to an interactive display chassis is also described in detail below. A plastic mounting frame is bonded to an undersurface of a plastic surface layer to provide a unified interactive display top. The mounting frame can be configured to mount to the interactive display chassis. Fastener receptacles are provided on the plastic mounting frame, and corresponding mounting orifices for fasteners are provided on the interactive display chassis. As described below, the mounting orifices are configured for alignment with the receptacles on the plastic mounting frame. The interactive display top can thus be removably coupled to the interactive display chassis with the fasteners. 
   This Summary has been provided to introduce a few concepts in a simplified form that are further described in detail below in the Description. However, this Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 

   
     DRAWINGS 
     Various aspects and attendant advantages of one or more exemplary embodiments and modifications thereto will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a simplified cross-sectional view of a spill resistant top surface for an interactive display; 
       FIG. 2  is a simplified cross-sectional view of a removable spill and tamper-resistant top surface for an interactive display; 
       FIG. 3  is a top plan view of a removable spill and tamper-resistant top surface for an interactive display, with hidden lines showing the location of fastener receptacles; 
       FIG. 4  is another cross-sectional view of a removable spill and tamper-resistant top surface for an interactive display; 
       FIG. 5  is yet another cross-sectional view of a removable spill and tamper-resistant top surface for an interactive display; 
       FIG. 6  is still another cross-sectional view of a removable spill and tamper-resistant top surface for an interactive display; 
       FIG. 7  is an inner side elevation view of a mounting rail having a fastener receptacle; 
       FIG. 8  is a top plan view of a mounting rail showing a fastener receptacle; 
       FIG. 9  is a bottom view of a mounting rail having a fastener receptacle; 
       FIG. 10  is a cross-sectional end view of a mounting rail having a fastener receptacle; 
       FIG. 11  is a schematic diagram of an exemplary interactive display table having an internal personal computer; and 
       FIG. 12  is schematic diagram of another embodiment of an exemplary interactive display table coupled to an external personal computer. 
   

   DESCRIPTION 
   Figures and Disclosed Embodiments Are Not Limiting 
   Exemplary embodiments are illustrated in referenced Figures of the drawings. It is intended that the embodiments and Figures disclosed herein are to be considered illustrative rather than restrictive. Furthermore, it should be understood in the following description and claims that when lists of alternatives are offered using the conjunctive form “and” that what is meant is “and/or.” 
     FIG. 1  is a simplified cross-sectional view of a spill and vandalism resistant top surface  100  for an interactive display. As depicted in  FIG. 1 , top surface  100  includes a top layer  101  that is affixed to a chassis top support  103   a  and  103   b , which is illustrated in cross-section. A support layer  102  is held in a generally fixed position by the attachment of top layer  101  to mounting frame rails  103   a  and  103   b , which can be attached to an underlying support chassis of an interactive display. Top surface  100  thus provides a smooth, ridgeless, spill resistant and vandal resistant user display surface. In one implementation top layer  101  is made from a plastic, such as an acrylic plastic. Furthermore, top layer  101  can be selected for particular desired tactile properties, such as slipperiness or high coefficient of friction. Top layer  101  can also be selected for durability, shatter resistance, scratch resistance, and chemical resistance properties, and for optical properties such as contrast, diffusion, and tint. In one implementation, as shown in  FIG. 1 , a radius  105  is provided around the periphery of top layer  101 , between the edge of the top layer and its upper surface. The radius eliminates sharp corners on the upper edge of top layer  101 . 
     FIG. 2  is a simplified cross-sectional view of a removable spill and tamper-resistant top surface  200  for an interactive display. As shown in  FIG. 2 , top surface  200  includes a top layer  201  having an upper surface  211  and a lower surface  212 . Also depicted in cross-section in  FIG. 2  is a mounting frame, identified as mounting frame portions  204   a  and  204   b . By way of illustration, a bonding surface  207  of mounting frame portion  204   b  is shown bonded to lower surface  212  of top layer  201 . Mounting frame portion  204   a  can be similarly bonded to bottom layer  212 . Fastener receptacles  221   a  and  221   b  are shown within mounting frame portions  204   a  and  204   b , respectively. Fasteners  210   a  and  210   b  are shown disposed within fastener receptacles  221   a  and  221   b , respectively. 
   A chassis top support, shown in cross-section as chassis top support portions  220   a  and  220   b , is configured to receive fasteners  210   a  and  210   b , respectively. By way of illustration, a through-hole (or orifice)  224  is illustrated in chassis top support portion  220   b  for receiving fastener  210   b , thereby enabling a lower surface  206  of mounting rail portion  204   b  to be affixed to a mounting surface  223  of chassis top support portion  204   b  with fastener  210   b . A support layer  213  can be held in fixed position against mounting frame portions  204   a - 204   b  by top layer  201  when fasteners  210   a - 210   b  are tightened to affix the top layer to the chassis top support. In one implementation, a peripheral edge radius  205  can be provided between upper surface  211  and an outer edge surface  209  of mounting rail portions  204   a  and  204   b . In another embodiment (not shown), fastener receptacle  221   a  can extend to an inner surface  208  of mounting rail portion  204   a . In still another embodiment, outer edge surface  209  can be smooth polished across the joint between mounting rail portion  204   a  and top layer  201 . When edge surface  209  is smooth polished, the bond between mounting rail portions  204   a - 204   b  and top layer  201  is indistinguishable to the human eye due to the type of adhesive used. Top surface  200  appears to essentially be a tamperproof one-piece unit, since there are no evident exposed edges or gaps that can be pried apart. 
   Top layer  201  can be any suitable material having the desired tactile, durability, optical, and other properties. In one implementation, top layer  201  is a high contrast, diffusing acrylic plastic. Support layer  213  can be any material having the desired optical properties and stiffness. In one implementation, support layer  213  is an optically transparent acrylic plastic. In another implementation, one or more surfaces of mounting rail portions  204   a - 204   b  are bonded to the top layer with a plastic welding adhesive, such as a product containing one or more glues or solvents. Examples of suitable adhesives or solvents include cyanoacrylate ester, methyl-ethyl-ketone, dichloromethane, and acetone. 
   Fasteners  210   a  and  210   b  can be any fastener suitable for removable attachment of top layer  201  to chassis top support  220   a  and  220   b . In one implementation fasteners  210   a - 210   b  can, for example, be a metal or plastic nut and bolt, a metal or plastic camlock, a screw, a dowel, and the like. Those of ordinary skill in the art will understand that a variety of suitable fasteners can be used for this purpose. 
     FIG. 3  illustrates an exemplary removable spill and tamper-resistant top surface  300  for an interactive display. A top layer  301  is bonded to a mounting frame  304  that includes a plurality of hidden receptacles  321 , having corresponding hidden fasteners  310 . In general, hidden receptacles  321  and hidden fasteners  310  are not visible to a user. It should be understood that  FIG. 3  is not drawn to scale, and further, that some features of  FIG. 3  are exaggerated in order to highlight a physical configuration of one implementation.  FIG. 3  further illustrates a viewing area  320 , which is surrounded by a shadow mask  330 . In one implementation, an edge radius  305  can optionally be provided between adjacent peripheral edges of top surface  300  and top layer  301 . In this implementation, of the top corners of top layer  301  are routed away and polished to form a smooth radius along the peripheral edge to increase user comfort. 
     FIG. 4  is cross-sectional view of a portion of another removable spill and tamper-resistant top surface  400  for an interactive display.  FIG. 4  illustrates one implementation for creating a mounting frame assembly from two or more layers (e.g., layers  404   a  and  404   b ). By selecting mounting frame assembly layers that have particular geometries and either slots or orifices provided in at least one of the layers, receptacles for fasteners (e.g.,  410 ) can be created by stacking and bonding the layers together with a suitable solvent or adhesive, examples of which are noted above. In this manner, for example, top layer  401  is bonded to layer  404   a  of the mounting rail assembly, and layer  404   b  of the mounting rail assembly is bonded to the layer  404   a . One or more additional layers (not shown) can optionally be bonded to layer  404   b  in a similar fashion, until the desired thickness of top surface  400  is achieved. 
     FIG. 5  is a cross-sectional view of a portion of yet another removable spill and tamper-resistant top surface  500  for an interactive display that includes a top layer  501  bonded to a mounting frame  504  having receptacles  506  that overlie orifices  508  for receiving fasteners  510  (only one receptacle/orifice and one fastener shown). Mounting frame  504  can be machined to remove material to create receptacle  506  for accommodating the head of fastener  510 . In this manner, top layer  501  can be removably attached to a chassis top support. 
     FIG. 6  is a cross-sectional view of a portion of still another removable spill and tamper-resistant top surface  600  for an interactive display. This Figure illustrates yet another approach for attaching a top layer  601  to a chassis top support (not shown) using a mounting frame  604  and a plurality of fasteners  610  (only one fastener shown). As depicted in  FIG. 6 , a diffuser sheet  622  is provided between top layer  601  and a support layer  612 , which can optionally also be bonded to mounting frame  604 . An additional transparent layer  614  is bonded to the lower surface of mounting frame  604  and traps support layer  612  in position. In one implementation, the support layer and the additional layer are optically transparent acrylic sheets, and the support layer is significantly thicker than top layer  601  in order to provide structural support to the top layer  601 . Fasteners  610  are disposed in receptacles  606  formed in mounting frame  604  and extend through orifices  608  that penetrate the mounting frame and additional transparent layer  614 . 
     FIG. 7  is a simplified inner side view of a portion of a mounting rail  704  having an open fastener receptacle  721 . As illustrated in  FIG. 7 , fastener receptacle  721  includes a transverse slot  721   a  in which a vertical slot  721   b  is generally centered. It should be understood that  FIG. 7  is not to scale and some features are exaggerated to highlight the physical configuration of the exemplary implementation. Transverse slot  721   a  of the fastener receptacle is sized and shaped for receiving a head or nut of a threaded fastener (not shown), while vertical slot  721   b  is sized for receiving the threaded shaft or shank of such a fastener.  FIG. 8  is a top plan view of mounting rail  704 , illustrating that the receptacle for a fastener can be embedded within the mounting rail in such a way that it is not be visible from a top view once mounting rail  704  is bonded to a lower surface of a top layer (not shown).  FIG. 9  is a bottom view of mounting rail  704 . 
     FIG. 10  is a cross-sectional end view of an interactive display top  1000  comprising a mounting rail  1004  bonded to the underside of a top layer  1001 . Mounting rail  1004  is shown as including a fastener receptacle  1021 . As illustrated in  FIG. 10  with hidden lines, the fastener receptacle includes a transverse slot  1021   a  for receiving a fastener head (or nut)  1025  and a vertical slot  1021   b  for receiving a threaded shaft or shank  1027  of a fastener  1010 . As illustrated in  FIG. 10 , the fastener receptacle is open on an internal face of mounting rail  1004 . This arrangement enables fastener  1010  to be removed after installation, thereby enabling interactive display top  1000  to be easily removed and replaced. 
   Exemplary Interactive Display 
   In  FIG. 11 , an exemplary interactive display table  60  is shown that includes a personal computer (PC)  20  within a frame  62  and which serves as both an optical input and video display device for the PC. In this cut-away Figure of the interactive display table  60 , rays of light  82   a - 82   c  used for displaying text and graphic images are generally illustrated using dotted lines, while rays of infrared (IR) light used for sensing objects on or just above a display surface  64  of the interactive display table  60  are illustrated using dash lines. In this exemplary embodiment of the interactive display table, display surface  64  can be a tamper proof and liquid resistant display surface according to any of the implementations described with reference to  FIGS. 1-10 . The perimeter of the table surface around the actual display area in the center is useful for supporting a user&#39;s arms or other objects, including objects that may be used to interact with the graphic images or virtual environment being displayed on display surface  64 . 
   IR light sources  66  preferably comprise a plurality of IR light emitting diodes (LEDs) and are mounted on the interior side of frame  62 . The IR light that is produced by IR light sources  66  is directed upwardly toward the underside of display surface  64 , as indicated by dash lines  78   a ,  78   b , and  78   c . The IR light from IR light sources  66  is reflected from any objects that are atop or proximate to the display surface after passing through a translucent layer  64   b  of the table, comprising a sheet of vellum or other suitable translucent material with light diffusing properties. As used herein and in the claims that follow in connection with objects positioned on or proximate to the interactive display surface, the term “adjacent to” is used with the intention that this term encompass both an object that is actually touching the interactive display surface as well as one that is just above the interactive display surface. Although only one IR source  66  is shown, it will be appreciated that a plurality of such IR sources may be mounted at spaced-apart locations around the interior sides of frame  62  to prove an even illumination of display surface  64 . The IR light produced by the IR sources may:
         exit through the table surface without illuminating any objects, as indicated by dash line  78   a;      illuminate objects on the table surface, as indicated by dash line  78   b ; or   illuminate objects a short distance above the table surface but not touching the table surface, as indicated by dash line  78   c.          

   Objects above display surface  64  include a “touch” object  76   a  that rests atop the display surface and a “hover” object  76   b  that is close to but not in actual contact with the display surface. Thus, both touch and hover objects are “adjacent to” the display surface, as that term is used herein. As a result of using translucent layer  64   b  under the display surface to diffuse the IR light passing through the display surface, as an object approaches the top of display surface  64 , the amount of IR light that is reflected by the object increases to a maximum level that is achieved when the object is actually in contact with the display surface. 
   A digital video camera  68  is mounted to frame  62  below display surface  64  in a position appropriate to receive IR light that is reflected from any touch object or hover object disposed above display surface  64 . The digital video camera  68  is equipped with an IR pass filter  86   a  that transmits only IR light and blocks ambient visible light traveling through display surface  64  along dotted line  84   a . A baffle  79  is disposed between IR source  66  and the digital video camera to prevent IR light that is directly emitted from the IR source from entering the digital video camera, since it is preferable that this digital video camera should produce an output signal that is only responsive to the IR light reflected from objects that are a short distance above or in contact with display surface  64  and corresponds to an image of IR light reflected from objects on or above the display surface. It will be apparent that digital video camera  68  will also respond to any IR light included in the ambient light that passes through display surface  64  from above and into the interior of the interactive display including ambient IR light that also travels along the path indicated by dotted line  84   a    
   IR light reflected from objects on or above the table surface may be:
         reflected back through translucent layer  64   b , through IR pass filter  86   a  and into the lens of digital video camera  68 , as indicated by dash lines  80   a  and  80   b ; or   reflected or absorbed by other interior surfaces within the interactive display without entering the lens of digital video camera  68 , as indicated by dash line  80   c.          

   Translucent layer  64   b  diffuses both incident and reflected IR light. Thus, as explained above, “hover” objects such as hover object  76   b  that are closer to display surface  64  will reflect more IR light back to digital video camera  68  than objects of the same reflectivity that are farther away from the display surface. The digital video camera  68  senses the IR light reflected from “touch” and “hover” objects within its imaging field and produces a digital signal corresponding to images of the reflected IR light that is input to the PC  20  for processing to determine a location of each such object, and optionally, the size, orientation, and shape of the object. It should be noted that a portion of an object, such as a user&#39;s forearm, may be above the table while another portion, such as the user&#39;s finger, is in contact with the display surface. In addition, an object may include an IR light reflective pattern or coded identifier, such as a bar code, on its bottom surface that is specific to that object or to a class of related objects of which that object is a member. Accordingly, the imaging signal from the digital video camera  68  can also be used for detecting each such specific object, as well as determining its orientation, based on the IR light reflected from its reflective pattern, in accord with the present invention. 
   The interactive display table is operable to recognize an object and/or its position relative to the interactive display surface  64  by detecting its identifying characteristics using the IR light reflected from the object. The logical steps implemented to thus detect and identify an object and its orientation are explained in the commonly-assigned patent applications, including application Ser. No. 10/814,577 entitled “Identification Of Object On Interactive Display Surface By Identifying Coded Pattern,” and application Ser. No. 10/814,761 entitled “Determining Connectedness And Offset Of 3D Objects Relative To An Interactive Surface,” both of which were filed on Mar. 31, 2004. 
   PC  20  may be integral to interactive display table  60  as shown in  FIG. 11 , or alternatively, may instead be external to the interactive display table, as shown in the embodiment of  FIG. 12 . In  FIG. 12 , an interactive display table  60 ′ is connected through a data cable  63  to an external PC  20  (which includes optional monitor  47 , as mentioned above). Alternatively, external PC  20  can be connected to interactive display table  60 ′ via a wireless link (i.e., WiFi or other appropriate radio signal link). As also shown in this FIGURE, a set of orthogonal X and Y axes are associated with display surface  64 , as well as an origin indicated by “0.” While not discretely shown, it will be appreciated that a plurality of coordinate locations along each orthogonal axis can be employed to specify any location on display surface  64 . 
   If an interactive display table  60 ′ is connected to an external PC  20  (as in  FIG. 12 ) or to some other type of external computing device, such as a set top box, video game, laptop computer, or media computer (not shown), then interactive display table  60 ′ comprises an input/output device. Power for interactive display table  60 ′ is provided through a power lead  61 , which is coupled to a conventional alternating current (AC) source (not shown). Data cable  63 , which connects to interactive display table  60 ′, can be coupled to a USB 2.0 port, an Institute of Electrical and Electronics Engineers (IEEE) 1394 (or Firewire) port, or an Ethernet port on PC  20 . It is also contemplated that as the speed of wireless connections continues to improve, interactive display table  60 ′ might also be connected to a computing device, such as PC  20  via such a high speed wireless connection, or via some other appropriate wired or wireless data communication link. Whether included internally as an integral part of the interactive display, or externally, PC  20  executes algorithms for processing the digital images from digital video camera  68  and executes software applications that are designed to employ the more intuitive user interface functionality of interactive display table to good advantage, as well as executing other software applications that are not specifically designed to make use of such functionality, but can still make good use of the input and output capability of the interactive display table. As yet a further alternative, the interactive display can be coupled to an external computing device, but include an internal computing device for doing image processing and other tasks that would then not be done by the external PC. 
   An important and powerful feature of interactive display table  60  or  60 ′ (i.e., of either of the embodiments of the interactive display table discussed above) is its ability to display graphic images or a virtual environment for games or other software applications and to enable an interaction between the graphic image or virtual environment visible on display surface  64  and identify objects that are resting atop the display surface, such as an object  76   a , or are hovering just above it, such as an object  76   b.    
   Again referring to  FIG. 11 , interactive display table  60  includes a video projector  70  that is used to display graphic images, a virtual environment, or text information on display surface  64 . The video projector is preferably of a liquid crystal display (LCD) or digital light processor (DLP) type, or a liquid crystal on silicon (LCoS) display type, with a resolution of at least 640×480 pixels. An IR cut filter  86   b  is mounted in front of the projector lens of video projector  70  to prevent IR light emitted by the video projector from entering the interior of the interactive display table where the IR light might interfere with the IR light reflected from object(s) on or above display surface  64 . Video projector  70  projects light along dotted path  82   a  toward a first mirror assembly  72   a . First mirror assembly  72   a  reflects projected light from dotted path  82   a  received from video projector  70  along dotted path  82   b  through a transparent opening  90   a  in frame  62 , so that the reflected projected light is incident on a second mirror assembly  72   b . Second mirror assembly  72   b  reflects light from dotted path  82   b  along dotted path  82   c  onto translucent layer  64   b , which is at the focal point of the projector lens, so that the projected image is visible and in focus on display surface  64  for viewing. 
   Alignment devices  74   a  and  74   b  are provided and include threaded rods and rotatable adjustment nuts  74   c  for adjusting the angles of the first and second mirror assemblies to ensure that the image projected onto the display surface is aligned with the display surface. In addition to directing the projected image in a desired direction, the use of these two mirror assemblies provides a longer path between projector  70  and translucent layer  64   b  to enable a longer focal length (and lower cost) projector lens to be used with the projector. 
   The foregoing discussions describe an interactive display device in the form of interactive display table  60  and  60 ′. Nevertheless, it is understood that the interactive display surface need not be in the form of a generally horizontal table top. The principles described in this description of the invention suitably also include and apply to display surfaces of different shapes and curvatures and that are mounted in orientations other than horizontal. Thus, although the following description refers to placing physical objects “on” the interactive display surface, physical objects may be placed adjacent to the interactive display surface by placing the physical objects in contact with the display surface, or otherwise adjacent the display surface. Clearly, the benefit of an easily replaceable vandal resistant and liquid spill resistant display surface as explained above apply regardless of the orientation of the interactive display. 
   It is also recognized that any of the implementations of a vandal and liquid resistant interactive display surface as discussed above may be useful in connection with interactive displays that do not include a projector for projecting images on the display surface, but instead use a different display technology, such a panel of liquid crystal display (LCD) elements, or other type of display technology. The interactive display surface may also use other techniques for sensing objects on or adjacent to the display surface other than the optical technique discussed above. Accordingly, it will be understood that the exemplary display surfaces described above in connection with  FIGS. 1-10  are not limited to any specific type of display or sensing technology, but can be benefit almost any type of interactive display system. 
   Method of Attaching Display Top to Interactive Display Chassis 
   Another aspect of this technology is directed to an exemplary method for attaching a liquid and tamper resistant top to an interactive display chassis. A plastic mounting frame can be bonded to an undersurface of a plastic surface layer to provide a unified interactive display top that is readily removed and replaced, and which is liquid spill and vandal resistant. The plastic mounting frame can be bonded using a plastic welding adhesive such as Weld On 16™. Plastic welding solvents/adhesives and techniques are well known to those in the art, and therefore will not be discussed in further detail. 
   The mounting frame can be configured to be mounted to the interactive display chassis. In one implementation, fastener receptacles are provided on the plastic mounting frame, and corresponding mounting orifices for fasteners are provided on the interactive display chassis. The receptacles and orifices can be of any size and shape appropriate for receiving fasteners, such as nuts and bolts, screws, cam-locks, and other removable fastener types. As described below, the mounting orifices are configured for alignment with the receptacles on the plastic mounting frame. The interactive display top can thus be removably coupled to the interactive display chassis with the fasteners, so that the interactive display top can be easily removed and replaced, as necessary. In one implementation, an interactive display (e.g., as described above, for example, with reference to  FIGS. 11 and 12 ) of a given dimension can be provided with a standardized fastener receptacle and orifice pattern, so that mass-produced interactive display tops having the standardized receptacle pattern can be interchanged on different interactive display chassis. 
   Another method implementation includes the additional step of providing the interactive display top with a support layer that is coupled to the chassis top. The support layer can be of any generally optically transparent material, such as plastic and the like, that can provide additional structural support to the display top when it is mounted on the display chassis. In one implementation the support layer is an acrylic plastic that is selected for optical transparency, and which is substantially thicker than a top layer of the display surface. 
   Yet another implementation includes the additional steps of forming a radius on at least a portion of an edge of the liquid and tamper resistant top layer, and then smooth polishing at least part of the edge of the interactive display top. The edge radius can have a radial dimension that provides a comfortable working surface for a user. Smooth polishing of the edge of display top renders the seam between the welded mounting frame and the surface layer nearly invisible to the naked eye, and provides a tamper-resistant display top. 
   Although the present invention has been described in connection with the preferred form of practicing it and modifications thereto, those of ordinary skill in the art will understand that many other modifications can be made to the present invention within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow.