Abstract:
Exemplary embodiment disclosed herein provide a point-of-sale advertising system for use with a display case having a front glass sheet positioned in front of a cavity for accepting goods, the system containing a transparent LCD positioned behind the front glass sheet, and a plurality of LEDs positioned adjacent to one pair of opposing edges of the LCD and arranged so that light which is emitted from the LEDs is directed backwards towards the cavity. Further embodiments may also contain a door assembly and frame surrounding the front glass sheet and LCD, a switch positioned to determine when the door assembly is open or closed, and electrical circuitry adapted to turn off the LEDs when the door is open and turn on the LEDs when the door is closed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to co-pending U.S. Application No. 61/546,809, filed on Oct. 13, 2011 and incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    Embodiments generally relate to a transparent liquid crystal display (LCD) positioned adjacent to the display glass in a display case. Embodiments include a system and method for backlighting the LCD as well. 
       BACKGROUND OF THE ART 
       [0003]    Display cases are used in a number of different retail establishments for illustrating the products that are available for sale. In some instances these display cases may be coolers or freezers which are placed in grocery stores, convenience stores, gas stations, restaurants, or other retail establishments. In other instances these display cases may be non-refrigerated transparent containers used in a jewelry or watch store, bakery, deli, antique shop, sporting goods store, electronics store, or other retail establishments. While the design and appearance of the product itself does provide some point-of-sale (POS) advertising, it has been found that additional advertising at the POS can increase the awareness of a product and in turn create additional sales. 
         [0004]    Most retail establishments already contain some POS advertising, and depending on the type of establishment the proprietor may want to limit the amount of ‘clutter’ in the retail area—resulting in a very limited space for additional POS advertising. It has now become desirable to utilize the transparent glass that is typically placed in display cases with additional POS advertising. Most notably, it has been considered that transparent LCDs may be positioned along with the transparent glass and could display additional advertising materials while still allowing a patron to view the products inside the display case. 
       SUMMARY OF THE EXEMPLARY EMBODIMENTS 
       [0005]    One exemplary embodiment provides a transparent LCD within the door of a display case. The LCD may be sandwiched between a pair of glass substrates. A plurality of LEDs may be positioned within the door assembly to provide additional illumination of the interior of the display case, reflecting and refracting off the products within the display case, effectively creating a backlight for the transparent LCD. The assembly may contain a switch so that an electronic controlling unit can detect when the door is open or closed. When closed, the LEDs are illuminated. When open, the LEDs are preferably off, but may be simply reduced in power. In some embodiments the LEDs may remain on even when the door is opened. 
         [0006]    Another exemplary embodiment provides a transparent LCD within the front glass assembly of a display case. In these embodiments, the LEDs may remain on whenever the LCD is displaying an image. Here, the LCD may be positioned behind a front glass. In any of the embodiments, the video data for the LCD may be provided by CAT-V cable. Also in any of the embodiments, the LEDs may be positioned along opposing edges of the assembly or along all edges of the assembly. 
         [0007]    The foregoing and other features and advantages of the present invention will be apparent from the following more detailed description of the particular embodiments, as illustrated in the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    A better understanding of an exemplary embodiment will be obtained from a reading of the following detailed description and the accompanying drawings wherein identical reference characters refer to identical parts and in which: 
           [0009]      FIG. 1  is a perspective illustration of a display case containing an exemplary embodiment of the transparent LCD. 
           [0010]      FIG. 2  is a sectional view showing the interior of the display case shown in  FIG. 1 . 
           [0011]      FIG. 3  is a rear elevation view of the door assembly from the embodiment shown in  FIG. 1 . 
           [0012]      FIG. 4  is a logic flow chart showing one embodiment for controlling the LED lighting for the transparent LCD. 
           [0013]      FIG. 5A  is an illustration of an embodiment of the transparent LCD used with a vending machine. 
           [0014]      FIG. 5B  is an illustration of an embodiment of the transparent LCD built within the counter of a general retail establishment. 
           [0015]      FIG. 5C  is an illustration of an embodiment of the transparent LCD used with a bakery display case. 
           [0016]      FIG. 6  is a side elevation view of an exemplary front glass assembly. 
           [0017]      FIG. 7  is a rear elevation view of an exemplary front glass assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The invention is described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. 
         [0019]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
         [0020]    Embodiments of the invention are described herein with reference to illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
         [0021]    Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
         [0022]      FIG. 1  is a perspective illustration of a display case  100  containing an exemplary embodiment of the transparent LCD  90  and  91 . The display case  100  typically contains a plurality of products  57  which are offered for sale. As shown in the figure, transparent LCD  90  is displaying an advertising graphic while transparent LCD  91  is clear, showing a view similar to a traditional display case. The front portion of the door assembly  60  may be described in two parts. The first is a transparent portion  55  which contains the LCD  90 . The second is a masked portion  50  which may allow room for various electrical components to run the LCD and backlighting. The section line  2 - 2  is shown as a vertical line, which cuts horizontally through the display case  100 . 
         [0023]      FIG. 2  is a sectional view showing the interior of the display case  100  shown in  FIG. 1 . Again, various products  57  are shown within the interior of the display case  100 . The transparent LCD  91  is preferably sandwiched between two pieces of glass, a front glass  190  and a rear glass  191 . As known in the art, a transparent LCD typically contains the core elements of a traditional LCD (front/rear polarizers, electrical controlling layer/TFT array, and color glass) with the notable lack of a traditional direct backlight. These LCDs are typically ‘normal white’ such that when zero volts are applied, the cells are substantially transparent, and as the voltage increases, the cells darken. 
         [0024]    A switch  180  is preferably positioned so that it can sense whether the door assembly  60  has been opened. The switch  180  may be attached to the rear portion of the door assembly  60  or to the door jamb  175 . The switch  180  may be any one of the following: push button, push to make, push to break, or any electrical component that can break an electrical circuit. The operation of the switch  180  is described more fully below. 
         [0025]    As known in the art, LCDs act as a light filter and thus require light to pass through the device in order to create an image. Here, to increase the luminance through the LCD  91 , a plurality of LEDs  126  have been positioned along the top of the door assembly  60  along with another plurality of LEDs  125  which are positioned along the bottom of the door assembly  60 . While both sets  125  and  126  are not required, it has been found that utilizing both top and bottom LEDs  125  and  126  results in the greatest luminance and uniformity of the light. The LEDs  125  and  126  may be positioned adjacent to the LCD  91  and between the front glass  190  and rear glass  191 . Further, the LEDs  125  and  126  may be placed behind the masking portion  50  of the door assembly  60  so that the LEDs are not visible to a patron. 
         [0026]    An optional light diffusing element may be positioned between the LEDs  125  and  126  and the products  57 . However, as shown in the figure, the light from the LEDs  125  and  126  may be permitted to bounce and scatter off various surfaces within the interior of the display case  100 . Most notably, the light from the LEDs  125  and  126  may bounce/scatter off the products  57 , both increasing the visibility of the products  57  as well as increasing the uniformity of the light emitted through the LCD  91 . The light from the LEDs  125  and  126  may also bounce/scatter off the interior surfaces of the display case. The LEDs  125  and  126  are generally positioned so that the primary direction of emitted light is towards the interior cavity of the display case  100 . 
         [0027]      FIG. 3  is a rear elevation view of the door assembly from the embodiment shown in  FIG. 1 . The masking portion  50  is shown surrounding the LCD  91 . Several electronic components may be positioned behind the masking portion  50 . A first power supply  325  may be in electrical communication with the LEDs  125 , which are preferably positioned along the bottom edge of the door assembly  60  and below the LCD  91 . A second power supply  326  may be in electrical communication with the LEDs  126 , which are preferably positioned along the top edge of the door assembly  60  and above the LCD  91 . In other embodiments, the LEDs may be positioned along the vertical edges (i.e. left and right) of the door assembly  60  rather than the horizontal edges (i.e. top and bottom). In still further embodiments, the LEDs may be position along all of the edges of the door assembly (i.e. top, bottom, left, and right). 
         [0028]    In some embodiments, a single power source may be placed in electrical communication with both sets of LEDs  125  and  126 . If two power supplies  325  and  326  are used, they are preferably each in electrical communication with an electrical processor unit  300 , which may be used to direct the amount of power to be sent to each set of LEDs. Even if two power supplies are not used, the sole power supply may preferably be in electrical communication with the electrical processor unit  300 . Additionally, the switch  180  is preferably in electrical communication with the electrical processor unit  300 . The electrical processor unit  300  may comprise any one of the following: EPROM, EEPROM, microprocessor, RAM, CPU, or any form of software driver capable of reading electrical signals from the switch  180  and controlling the power sent to the LEDs. The timing and control board (TCON) for the LCD  91  may be contained within the electrical processor unit  300  and thus is preferably in electrical communication with the LCD  91 . 
         [0029]    A power input  350  may also be in electrical communication with the electrical processor unit  300 . The power from power input  350  may then be sent to the power supplies  325  and  326  or the power may be distributed directly from the power input  350  to the power supplies  325  and  326  without going through the electrical processor unit  300 . A video signal input  375  may also be in electrical communication with the electrical processor unit  300 . In an exemplary embodiment, the video signal input  375  would comprise a CAT-V cable. In other embodiments, the video signal input may instead comprise a wireless receiver. 
         [0030]      FIG. 4  is a logic flow chart showing one embodiment for controlling the LED lighting for the transparent LCD  91 . In some embodiments, this logic may provide at least a portion of the software for the electrical processor unit  300 . Once the software has started, the system would preferably read the data from the switch  180  to determine if the door is open or closed. If the door is closed, the LEDs are preferably turned on, to increase the luminance through the LCD as well as the appearance of the products. If the door is open, the LEDs are preferably turned off, so that a patron is not subject to the bright illumination of the LEDs. Of course, there should still be illumination within the interior of the display case, sometimes provided by traditional fluorescent lighting. Whether the door is currently open or closed, the system should return to re-read the data from the sensor  180  to determine if the door&#39;s status has changed since the last check. This ‘loop’ is preferably run almost constantly, so that changes in the door&#39;s status can be almost instantaneously accounted for. 
         [0031]      FIG. 5A  is an illustration of an embodiment of the transparent LCD  450  used with a vending machine  400 .  FIG. 5B  is an illustration of an embodiment of the transparent LCD  450  built within the counter  500  of a general retail establishment.  FIG. 5C  is an illustration of an embodiment of the transparent LCD  450  used with a bakery display case  600 . In contrast to the embodiments described above, these embodiments do not contain a door or door assembly, but rather a front glass assembly  700 . 
         [0032]      FIG. 6  is a side elevation view of an exemplary front glass assembly  700 . In this embodiment, the LCD  450  is placed behind a front glass  455  and the LEDs  475 / 476  are positioned along the vertical edges of the front glass assembly  700 . Preferably, the LEDs  475 / 476  are positioned behind the masking portion  50 . 
         [0033]      FIG. 7  is a rear elevation view of an exemplary front glass assembly  700 . In this embodiment, a first set of LEDs  475  are positioned along the left vertical edge of the front glass assembly  700  and a second set of LEDs  476  are positioned along the right vertical edge of the front glass assembly  700 . A single power source  480  is in electrical communication with both sets of LEDs  475  and  476 . An electrical processor unit  715  is also preferably in electrical communication with the power source  480  as well as the LCD  450 . 
         [0034]    A power input  350  may also be in electrical communication with the electrical processor unit  715 . The power from power input  350  may then be sent to the power supply  480  or the power may be distributed directly from the power input  350  to the power supply  480  without going through the electrical processor unit  715 . A video signal input  375  may also be in electrical communication with the electrical processor unit  715 . In an exemplary embodiment, the video signal input  375  would comprise a CAT-V cable. In other embodiments, the video signal input may instead comprise a wireless receiver. 
         [0035]    Having shown and described a preferred embodiment of the invention, those skilled in the art will realize that many variations and modifications may be made to affect the described invention and still be within the scope of the claimed invention. Additionally, many of the elements indicated above may be altered or replaced by different elements which will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims.