Patent Publication Number: US-7210623-B2

Title: Printable shelf label

Description:
FIELD OF THE INVENTION 
     The present invention relates to an electronic shelf label assembly having as rewritable display and a printable overlay. 
     BACKGROUND OF THE INVENTION 
     Electronic shelf labels are becoming a popular and intelligent way to display product information on a shelf. The customer benefits by having all the information they need about the product, and the retailer benefits by having programmable information that can be readily changed by various electronic means. For example, prices can be kept up to date without printing new price changes. More permanent information can be printed on another portion of the electronic shelf label, such as a removable or permanent overlay that allows the electronic display to show through. 
     Exemplary electronic shelf labels as discussed above are shown and described in U.S. Pat. No. 5,111,196 issued to Hunt, U.S. Pat. No. 5,619,416 issued to Kosarew, U.S. Pat. No. 6,217,966 issued to Finster et al., and U.S. Pat. No. 6,552,663 issued to Swartzel et al. These patents describe electronic shelf labels that include a liquid crystal display, a mounting support, onboard electronics, a printable overlay, and a power source to provide viewability of the display at all times. One problem with the aforementioned devices is the need of a continuous power source and replacement of said power source on a regular basis. Without the power source, the display is blank. 
     To overcome the above problem, a bistable liquid crystal display that retains written information on the display in the absence of power can be used. One such electronic shelf label is shown and described in U.S. Pats. Nos. 5,751,257 and 6,253,190, both issued to Sutherland, which describe a system including an electronic shelf label having a bistable liquid crystal display for displaying price data and a Universal Product Code (“UPC”) bar code, wherein the information programmed in the display remains on the display in the absence of power. The shelf label has a set of synchronizing indicators and corresponding electrical contacts on the front side of the display, which are capable of interacting with a hand-held device that is connected to a central computer that contains inventory and price information. The hand held device can be used to read the UPC bar code on the shelf label and update or write corresponding price information on the label. Both the UPC and the price information are shown on the display. 
     Including the UPC as a writable element on the shelf label significantly increases the complexity and cost of the shelf label. The resolution needed to produce UPC information requires 113 modules of data, and therefore a corresponding number of contacts on the front of the display. The UPC for a product typically does not change over the life of the product. Other static information, for example, a human readable description of the product, a unit identification (e.g. per oz. or per 100 sheets), or the like, can also be desirable on the display. The placement of static information such as the UPC in writable form on the shelf label unnecessarily complicates the display structure of the label. 
     One solution to the aforementioned problem is shown and described in U.S. Pat. No. 6,637,650 issued to Capurso et al. It describes an electronic shelf label including a bistable liquid crystal display, which displays information even in the absence of power. A printable overlay containing the bistable liquid display is provided on a printable overlay sheet. The retailer can print static information on the overlay sheet, peel off the overlay containing the display, and attach it to a support. The support provides electrical continuity to the display by way of conductive adhesive and embedded conductive strips. Once attached to the conductive adhesive, the embedded conductive strips in the support provide a front contact outside the overlay area for electronic interfacing in order to change the information on the display. However, careful alignment of the overlay with the embedded conductive strips in the support is required to provide power to the display. Further, because the display is part of the overlay, and is not powered as provided to the retailer, it is difficult to test the functionality of the display before assembly with the support. 
     There is a need for a shelf label having a conductively mounted display wherein the functionality of a support for the display and the display can be tested prior to reaching the retailer, and wherein static information can be provided separately from the display, for example, on an overlay. 
     SUMMARY OF THE INVENTION 
     An electronic shelf label assembly and a method of making the same is described, wherein the assembly includes a support, a display, and a printable overlay. The support has a display area, an overlay area adjacent the display area, an exposed area adjacent the overlay area, and a plurality of conductive contacts, wherein each of the plurality of conductive contacts has a first conductive portion within the display area and a second conductive portion in the exposed area. The display has a substrate, and a plurality of electrically conductive contact pads on the substrate. The display is attached to the display area of the support such that the first conductive portion of the conductive contacts of the support contact the electrically conductive contact pads of the display. The printable overlay has a window, and is attached to the overlay area of the support such that at least a portion of the display in the display area of the support is viewable through the window. 
     Advantages 
     The electronic shelf label assembly allows for pre-testing of the support and display prior to sale, updating of static information without effecting the display, updating of the display without effecting the static information, and viewing of the display information in the absence of power. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a character display; 
         FIG. 2  is a cross sectional view of a character display taken along lines  2 — 2  in  FIG. 1 ; 
         FIG. 3  is a front perspective view of a support with conductive strips inset into a surface of the support; 
         FIG. 4  is a perspective view of the front of a support having conductive strips inset into a surface of the support and conductive tape strips with adhesive backer liner positioned over the conductive strips; 
         FIG. 5  is a perspective view of a support assembly, including a support and character displays attached to the support; 
         FIG. 6  is a front view of a printable sheet with individual labels positioned in an array; 
         FIG. 7  is an exploded view of a shelf label assembly, including a printable overlay and support assembly; 
         FIG. 8  is an exploded section view along line  8 — 8  of  FIG. 7 ; 
         FIG. 9  is a shelf label assembly; and 
         FIG. 10  is a back perspective view of a shelf label assembly having a bracket for attaching the electronic shelf label to an existing shelf label rail system. 
     
    
    
     The drawings are exemplary only, and depict various embodiments of the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     An electronic shelf label assembly including a display and printable overlay on a support can be sold to retail outlets for use in displaying changeable merchandise information. Static merchandise information can be provided on the assembly by the overlay, while changeable information can be written on the display and viewed through a window of the overlay. The support assembly can be pre-tested prior to sale to ensure display functionality. The overlay can be printed by the retailer and affixed to a corresponding support. A new overlay can be generated and affixed to the support if typically static information about the product changes. The term “static information” as used herein refers to product information which does not change often, for example, unit size, unit weight, product name, manufacturer name, trademark, UPC, bar code, or the like. Price changes can be made by updating the display electronically. The electronic shelf label assembly and methods of making it are described in detail with reference to the accompanying figures. 
     As shown in  FIGS. 1 and 2 , a character display  10  can be constructed by forming a conductive common electrode layer  20  on a substrate  15 . The substrate can be any suitable material, for example, glass or plastic. When the substrate is plastic, it can be flexible, for example, a flexible self-supporting plastic film. “Plastic” means a polymer, usually made from polymeric synthetic resins, which can optionally be combined with other ingredients, such as curatives, fillers, reinforcing agents, colorants, and plasticizers. Plastic includes thermoplastic materials and thermosetting materials. Where a flexible plastic substrate is used, it can be reinforced with a hard coating, for example, an acrylic coating. The coating can have a thickness of from 1 to 15 microns, for example, from 2 to 4 microns. Various suitable hard coatings can be used, dependent upon the substrate material, and include a mixture of UV-cured polyester acrylate and colloidal silica, known as “Lintec” by Lintec Corporation of Tokyo, Japan, and an acrylic coating sold as Terrapin® by Tekra Corporation, New Berlin, Wis. 
     The common electrode layer is a conductive layer. It can include one or more metal oxide. A primary metal oxide can be indium oxide, titanium dioxide, cadmium oxide, gallium indium oxide, niobium pentoxide, or tin dioxide, for example. A secondary metal oxide can also be in the conductive layer, and can be, for example, an oxide of cerium, titanium, zirconium, hafnium and/or tantalum. See, U.S. Pat. No. 5,667,853 to Fukuyoshi et al. Transparent conductive oxides that can be used include, but are not limited to, ZnO 2 , Zn 2 SnO 4 , Cd 2 SnO 4 , Zn 2 In 2 O 5 , MgIn 2 O 4 , Ga 2 O 3 —In 2 O 3 , or TaO 3 . According to various embodiments, the common electrode layer can be tin-oxide, indium-tin-oxide (ITO), or polythiophene. The common electrode layer can be an opaque electrical conductor formed of metal such as copper, aluminum or nickel. If the conductive layer is an opaque metal, the metal can be a metal oxide to create a light absorbing conductive layer. The common electrode layer can be formed by any known method, including low temperature sputtering techniques and direct current sputtering techniques, such as DC-sputtering or RF-DC sputtering, depending upon the material or materials of the underlying layer. The common electrode layer can be preferably patterned, for example, into a plurality of electrodes. 
     A layer of bistable liquid crystal material  25  can be deposited over at least a portion of the conductive common electrode layer  20 , leaving an exposed area  22  of the conductive common electrode layer  20 . Bistable liquid crystal material can be used so that the display requires no power to maintain its state once electronically written. Bistable display materials that can be used include, for example, cholesteric nematic liquid crystal such as disclosed in U.S. Pat. No. 5,695,682, and electrophoretic particles such as those manufactured by Gyricon, LLC of Ann Arbor, Mich., and E-ink Corporation of Cambridge, Mass. The bistable liquid crystal material  25  can be formed on the conductive common electrode layer  20  by roll coating, placement of a preformed layer, or any other means known to practitioners in the coating arts. Application of fields of various intensity and duration change the state of bistable materials from a reflective to a transmissive state. These materials have the advantage of maintaining a given state indefinitely after the field is removed. Examples of suitable cholesteric liquid crystal materials include, but are not limited to, Merck BL112, BL118 or BL126, available from EM Industries of Hawthorne, N.Y. 
     Electrically conductive character segments  35  can be formed over the bistable liquid crystal material layer  25  by thick film printing, sputter coating, or other printing means. The conductive character segments can be any known aqueous conductive material, for example, carbon, graphite, or silver. An exemplary material is Electrodag 423SS screen printable electrical conductive material from Acheson Corporation. The conductive character segments  35  can be arranged to form numbers 0–9, a slash, a decimal point, a dollar sign, a cent sign, or any other alpha-numeric character or symbol. 
     A dielectric layer  30  such as deionized gelatin can be formed over the conductive character segments  35  by standard printing or coating techniques. Via holes  45  can be formed over each conductive character segment  35  by the absence of dielectric layer  30  over at least a portion of each conductive character segment  35 , or by removing a portion of the dielectric layer  30  over each conductive character segment  35 , for example, by ablation or chemical etching. 
     Electrically conductive traces  40  can be formed over the dielectric layer  30  by printing or coating techniques. One or more electrically conductive trace  40  can flow through a via hole  45  on formation, making electrical contact with the conductive character segments  35 . The conductive traces  40  can extend from character segments  35  to the exposed area  22  along a side of the display  10 , where the conductive trace  40  forms a contact pad  50  in exposed area  22 . 
     The contact pads  50  can be any conductive material, for example, silver or carbon. The conductive pads  50  can be formed with the conductive traces  40 , or separately therefrom. Conductive pads  50  that are not formed with the conductive traces  40  are coated on dielectric layer  30 . A via hole  45  extends from the conductive pads  50  through dielectric layer  30  to the common electrode layer  20 . The exposed area  22  and the contact pads  50  thereon can be formed along one side of the display  10 , along multiple sides of the display  10 , or in one or more locations on the display not including a conductive character segment  35 . According to various embodiments, the contact pads  50  can be formed in exposed area  22  along one edge of the display  10 . The contact pads  50  can be placed linearly or grouped, such as in a pattern, for example, a square or rectangle, in an exposed area  22 . 
     The optical state of the bistable liquid crystal material  25  between the conductive character segment  35  and the common electrode layer  20  can be changed by selectively applying drive voltages to the corresponding contact pad  50  that is electrically connected to the conductive character segment  35  through a conductive trace  40  and to the electrode layer  20  by direct contact. Once the optical state of the bistable material has been changed, it remains in that state indefinitely without further power being applied to the electrodes. Methods of forming the character display  10  are known to practitioners in the art, and are described, for example, in U.S. Ser. No. 10/134,185, filed Apr. 29, 2002 by Stephenson et al. 
     The character display  10  can be attached to a support  55 .  FIG. 3  shows a frontal perspective view of an embodiment of the support  55 . The support  55  can be any suitable material, for example, plastic, glass, ceramic or the like. The support  55  can be shaped by any means known in the art. According to various embodiments wherein the support is plastic, the support  55  can be injection molded, press-molded, roll sheet, extruded, or the like. As shown in  FIG. 3 , the support  55  can have a plurality of conductive strips  70  inset within the support  55 , or formed along a surface of support  55 . Although conductive inlay strips are exemplified in  FIG. 3 , other forms of a conductive contact material can also be used in or on support  55 , so long as the form of the conductive contact is electrically conductive and is capable of conveying such electrical charges to the conductive traces and common electrode layer of the display directly, or through the contact pad. For example, the conductive contact can be metal or a conductive plastic. It can be applied to the support by printing, as an appliqué, or other like techniques. The conductive contact can also be formed as part of the support, for example, by molding the conductive contact into the support. 
     According to various embodiments, the support  55  can be injection molded with conductive inlay strips  70  molded within it. The support  55  can have a recess  65  designed to accept printable overlay  100  for proper alignment of the overlay  100  onto the support  55 . The recess  65  can be of sufficient size to accommodate the overlay  100  or can be larger than the overlay  100 . The recess  65  can be of the same or a different shape as the overlay  100 . The support  55  can have one or more clearance recess  60  for receiving one or more character display  10 . Clearance recess  60  can be of sufficient size to enable the display  10  to adhere flatly onto support  55  in recess  60 . The display  10  can fit into clearance recess  60  such that the visible surface of the display  10  is co-planar or nearly co-planar with either the surface of recess  65 , if present, or the surface of the support  55 . According to various embodiments, both recess  65  and clearance recess  60  can be present in support  55 , as shown in  FIG. 3 . 
     As exemplified herein, the support has a recess for receiving a display, and a recess for receiving a printable overlay. The recesses provide advantages including clear indication of attachment points for the display and overlay, and provision of a planar or nearly planar surface on the shelf tag assembly. The attachment point for the display can be indicated by the recess as described; by a raised area of the support within which the display can be positioned; by a physical indication of the display area, for example, by a depression or raised area of the support immediately surrounding the display area, including tabs or lines; by visual marks, for example, at least a portion of a printed outline; or by placement of the electrical contacts. The attachment area for the overlay can be indicated by the recess as described; by a raised area of the support within which the display can be positioned; by a physical indication of the display area, for example, by a depression or raised area of the support immediately surrounding the display area, including tabs or lines; by visual marks, for example, at least a portion of a printed outline; or by alignment of the window of the overlay with the display. 
     The character display  10  can be attached to the conductive strips  70  of the support  55  through contact pads  50  with an adhesive. The adhesive can be in the form of a paste, sheet, layer, solvent coating, or the like, and can be coated on or adhered to the conductive strips  70 , the contact pads  50 , or both. According to various embodiments, the adhesive is a conductive adhesive. The conductive adhesive can be anisotropic.  FIG. 4  depicts a front view of support  55  with conductive strips  70 , having strips of conductive adhesive tape  75  applied over the conductive inlay strips  70 . Conductive adhesive tape  75  can be applied with a backer liner  80  on one side, such that the adhesive tape  75  is not exposed. Backer liner  80  can be removed to expose conductive adhesive  75  for adhesion to the conductive contact pads  50  of character display  10  as the display  10  is attached to support  55 . Placement of the conductive adhesive  75  between conductive contact pads  50  on display  10  and conductive inlay strips  70  provides electrical continuity between the conductive character segments  35  in character display  10  and the conductive inlay strips  70 . According to various embodiments, the conductive strips  70  can be in direct physical contact with the contact pads  50 . 
       FIG. 5  illustrates a completed support assembly  110  having display  10  inserted into the support  55  such that each contact pad (not shown) of the display  10  is conductively connected to an inlay strip  70 . The conductive inlay strips  70  are exposed on a surface of support  55  to allow electronic programming of the changeable conductive characters segments  35  on display  10 . A printable overlay can be placed on support assembly  110  to provide static information. 
     A printable overlay can be supplied in any suitable printable form, for example, as individual printable labels, as a printable roll of multiple separable overlays, or in sheet form. The printable overlay can be any material suitable for printing, for example, paper or plastic. A plastic printable overlay can be transparent or opaque. An opaque overlay of paper or plastic can be any color.  FIG. 6  shows a printable sheet  85  having a plurality of printable overlays  100 . According to various embodiments, a printable sheet  85  can include one or more overlay  100 . According to various embodiments, the printable sheet  85  can include an adhesive backing  90  and an adhesive backer liner  95 , as shown in  FIG. 6 , such that the overlays can be adhered to support assembly  110  by an adhesive backing  90 . According to various embodiments, each overlay  100  can be attached to support assembly  110  non-adhesively by use of a retainer, for example, tabs, slots, clips, brackets, or pegs on support  55  into or onto which the overlay  100  can be placed, respectively. 
     Each overlay  100  can have one or more window  105  corresponding to a position of a display  10  when the overlay  100  is placed on support assembly  110 . The window  105  can allow all or only a portion of display  10  to be viewed. The windows  105  can be perforated or die cut through the printable sheet  85 . According to various embodiments, the perforation or die cut can also extend through the adhesive backer liner  95  when present. Each printable overlay  100  can be die cut or formed by perforations through the printable sheet  100 . The printable overlay  100  can have readable static information  120 , for example, a bar code and/or item description, applied by printing. Printing can be performed by any known method, including but not limited to inkjet printing, thermal printing, electrophotography, and manual printing, for example, hand-lettering. The printed inks or colorants can be chosen for contrast to the overlay color. 
     According to various embodiments, the window in the overlay can be a transparent material, for example, a polymeric material or cellophane, that is adhesively secured to the overlay and capable of passing through a printer without damage, such as crinkling or melting of the transparent window. According to various embodiments, the entire overlay can be a transparent, printable material through which the display can be viewed. Where the entire overlay is transparent, the printing on the overlay should contrast the color of the support. For example, if the support is white, the print on the transparent overlay can be black, blue, red, green, or any color other than white. If the support is black, the print on the transparent overlay can be white, yellow, or any other contrasting color readable on a black background. A transparent window material can protect the display from environmental hazards and damage by touch. 
       FIG. 7  is an exploded view of a shelf label assembly  115 . The shelf label assembly  115  is shown with printable overlay  100  having an adhesive backing  90 , wherein the printable overlay  100  has been separated from the adhesive backer liner  95  of printable sheet  85  and is ready for attachment to the support assembly  110 . 
     A cross-sectional exploded view of the shelf label assembly  115  along line  8 — 8  of  FIG. 7  is depicted in  FIG. 8 . As shown in  FIG. 8 , the printable overlay  100  can overlap at least a portion of the display  10 . The contact pads  50  can overlap at least a portion of the conductive adhesive  75 , by which they are conductively attached to the conductive inlay strips  70 . The display  10  and conductive adhesive can fit within recess  60 , and the printable overlay  100  can fit within recess  65  of the support  55 . 
       FIG. 9  is a front view of a completed shelf label assembly  115 . At least a portion of the conductive inlay strips  70  are exposed on the support  55  outside the area covered by the printable overlay  100  to allow electrical contact through the strips  70  to the display.  FIG. 9  demonstrates a possible placement of static information  120 , a UPC, on the printable overlay  100 . Information can be printed anywhere on the printable overlay, and can include multiple types of information, for example, a UPC, product number, weight, size, store code, manufacturer, product name, trademark, image, and the like. Temporary information can also be printed on the printable overlay, with the understanding that a new overlay will be required when such information changes. The overlay  100  is shown in  FIG. 9  as covering most of the support  55  on the side from which the display is visible. The overlay  100  can cover a portion of the support  55  adjacent the display  10 . A secondary overlay can be printed to cover another portion of the support  55  not including the display  10 , or to cover or update information on the overlay  100  that has changed, thereby foregoing the need to print and attach a new overlay over or in place of an existing overlay  100 . 
     The shelf label assembly can be attached to a shelving unit through the support. Various shelving attachments include a clip; a tab; a bracket; a fastener, for example, a screw, nail, or adhesive; or any other attachment method known for securing two items. Where a physical retainer such as a tab, clip, or bracket is used, the physical retainer can be formed as, or attached to, part of the support, and can interact with the shelving unit. The physical retainer can be formed as or attached to part of the shelving unit, and interact with the support of the shelf label assembly.  FIG. 10  shows a rear perspective view of shelf label assembly  115 , wherein a bracket  125  is formed on the support  55  for attachment to an existing shelf tag rail system. 
     The shelf label assembly can be used in a retail or storage environment to provide product information which can be changed as needed by rewriting the display, changing all or a portion of the overlay, or a combination thereof. In use, one or more displays can be attached to a support as indicated on the support, a printable overlay can be printed with information, the overlay can be applied to the support including the one or more display, and the display can be written by electrically activating various display segments through the conductive inlay strips on the support. The support can be attached to a shelving unit or other display unit for viewing of the information on the display and overlay. 
     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. 
     PARTS LIST  
     
         
           10  display 
           15  substrate 
           20  common electrode layer 
           22  exposed area 
           25  bistable liquid crystal layer 
           30  dielectric layer 
           35  conductive character segment 
           40  conductive traces 
           45  via holes 
           50  tag contact pad 
           55  support 
           60  recess in support for tag 
           65  recess in support for printable overlay 
           70  conductive inlay strips 
           75  conductive adhesive strip 
           80  conductive adhesive backer liner 
           85  printable sheet 
           90  adhesive backing 
           95  adhesive backer liner 
           100  printable overlay 
           105  perforated window 
           110  support assembly 
           115  shelf label assembly 
           120  static information 
           125  bracket