Abstract:
A method of writing an electrically writable tag using a hand-held writing device includes the steps of providing an electrically writable tag having a plurality of electrical conductors located on a display surface of the tag, and a mechanical alignment feature including a detent for locating the tag with respect to a hand-held writing device; providing a hand-held writing device having a corresponding plurality of electrical contacts for simultaneously making contact with the electrical conductors of the tag, and a complementary alignment feature with a detent for locating the hand-held writing device with respect to the tag; and locating the hand-held writing device with respect to the tag, using the alignment features, and activating the hand-held writing device to write information on the tag.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a structure having a flexible display with front electrical contacts to the display. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 5,751,257 issued May 12, 1998, and U.S. Pat. No. 6,253,190 issued Jun. 26, 2001, both to Sutherland show a system including a programmable shelf tag 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 tag has a set of synchronizing indicators and corresponding electrical contacts on the frontside of the display. 
     The shelf tag is programmable 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 scan the synchronizing indicators to identify the location of the electrical contacts and supplies the electrical contacts with electrical signals to write appropriate information on the shelf tag. For inventory control and price updates, the hand-held device is used to first read the UPC bar code on the shelf tag. If a price needs to be updated, the hand-held device is then used to write the appropriate price information into the tag. The hand-held device is placed into contact with the shelf tag and is moved across the tag to sequentially make contact with each of the contacts on the front side of the display. A timing track is included on the front side of the display. The hand-held device reads the timing track optically and synchronizes the signal supplied to the respective contacts as the hand-held device is moved across the display. The display includes an alignment groove and the hand-held device includes a probe that is located in the alignment groove to position the contacts of the hand-held device relative to the contacts of the display. 
     One problem with the system as described by Sutherland is that including the UPC as a writable element on the shelf tag, significantly increases the complexity and cost of the shelf tag. The resolution needed to produce UPC information requires 113 modules of data, and therefore requires at least a corresponding number of contacts on the front of the display. 
     Another problem is that the hand-held device must be translated in a preferred direction (e.g. right to left) and within a preferred translation rate to properly program the display. Yet another problem is that translating the hand-held device across the contacts tends to wear out the contacts of the hand-held device and the shelf tag over time, necessitating replacement or repair of the contacts. A further problem with the method and apparatus disclosed by Sutherland is that the electronics of the hand-held device are complicated by the need to sequentially address the contacts of the display. 
     There is a need therefore for an improved writable display tag and hand-held programming device that avoids the problems noted above. 
     SUMMARY OF THE INVENTION 
     The need is met according to the present invention by a method and apparatus that includes an electrically writable tag having a plurality of electrical conductors located on a display surface of the tag, and a mechanical alignment feature including a detent for locating the tag with respect to a hand-held writing device; and a hand-held writing device having a corresponding plurality of electrical contacts for simultaneously making contact with the electrical conductors of the tag, and a complementary alignment feature with a detent for locating the hand-held writing device with respect to the tag. The hand-held writing device is located with respect to the tag, using the alignment features and activated to write information on the tag. 
     ADVANTAGES 
     The electrically writable tag and writing device of the present invention has the advantage that the writing device cooperates with the tag to make precise simultaneous alignment with all of the electrical contacts of the writable tag. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a front view of a label having a display element used with the present invention; 
         FIG. 2  is a back view of the label shown in  FIG. 1 ; 
         FIG. 3A  is a front perspective view of a support body for receiving the label shown in  FIG. 1 , 
         FIG. 3B  is a rear perspective view of the support body of  FIG. 3A  showing placement of an RFID transponder. 
         FIG. 4  is a perspective view of the support body with anisotropic conductive tape strips with adhesive backer liner positioned over the conductive strips; 
         FIG. 5  is a front view of a completed display tag assembly used with the present invention; 
         FIG. 6  is a perspective front view of a hand-held writing device used with the present invention; 
         FIG. 7  is a perspective back view of the hand-held writing device shown in  FIG. 6 ; 
         FIG. 8  is a partial sectional view of the hand-held writing device of  FIG. 7  taken along line A—A; 
         FIG. 9  is an exploded perspective view of one embodiment of a hand-held writing device according to the present invention; and 
         FIG. 10  is a functional block diagram of the hand-held writing device. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a label  10  includes one or more electronically writable display elements  15  constructed by forming a plurality of common conductive character electrodes on a substrate; coating and drying a liquid crystal gelatin dispersion over the common character electrodes, and printing conductive character elements over the common character electrodes. The display elements are mounted in windows  18  cut into a sheet of adhesive print medium having a printable surface  25 . The label is preferably made as shown in U.S. Ser. No. 10/134,185 filed Apr. 29, 2002 by Stephenson et al., which is incorporated herein by reference. 
     The perforated windows  18  allow character elements  20  on displays  15  to be viewed from the front printable side  25  of the label  10 . Printable surface  25  allows the addition of static readable information such as bar code and item description to be applied by a printer such as an ink jet printer. 
     The reverse side of label  10  shown in  FIG. 2  has an adhesive backing  30  to allow attachment to a support body  35  as well as attachment of the display elements  15  to the back side of the label  10 . Display elements  15  are attached to adhesive backing  30  to expose electrically conductive pads  22  on the back side of display elements  15 . The adhesive backing is covered with a removable liner until the tag is assembled. Prior to assembly, the printable surface  25  has information printed on it, for example, by an ink jet printer. 
       FIG. 3A  shows a front perspective view of a support body  35  having conductive strips  40  imbedded within it. A recess  45  positions label  10  on the support body  35  to form a display tag assembly as shown in FIG.  5 . Recesses  50  in support body  35  provide clearance for the display elements  15  to allow the label  10  to lay flat on support body  35 . Support body  35  is manufactured, for example, by injection molding plastic with conductive inserts to provide the conductive strips. Alternatively, the support body can be formed and the conductive strips applied subsequently. The display tag assembly may also include an RFID (radio frequency ID) transponder.  FIG. 3B  is a back view of the support body  35  showing a recess  46  for locating the RFID transponder  47  on the back of the support body  35 . 
     Referring to  FIG. 4 , electrical connection is provided between the conductive pads  22  on the display elements  15  and the conductive strips  40  in the support body  35  by anisotropically conductive adhesive strips  42  having a removable a backer liner  48  (shown partially removed). For assembly, the backer liner of the conductive adhesive strips  42  is removed, the releasable liner is removed from the back of the label  10 , and the label  10  is inserted into the recess  45  of the support body  35 . 
       FIG. 5  shows an assembled display tag assembly  55  with a label  10  adhered to the support body  35 . The character elements  20  on the display element  15  show through cut-out windows  18  in the label  10 . The conductive strips  40  are exposed along the bottom edge of the support body  35  allowing electrical contacts to be made between a hand-held writing device and the display elements  15 . The conductive strips  40  in turn contact the conductive pads  22  on the reverse side of the display elements  15  by way of the anisotropic conductive adhesive  42  thus enabling the state of the character elements  20  to be changed by applying a suitable electrical signal to the conductive strips  40 . 
     One element of information, which can be printed on the label, is a UPC bar code  60  Generally, the UPC bar code for a product is static and does not change for the life of the product. It therefore can be practically printed on the label  10 , as opposed to including it in the writable display portion of the label. A Universal Product Code Identification Number may also be stored in the RFID transponder  47 . Other information, such as the designation “price” and “price per unit” is normally printed adjacent the display elements, and a product description is normally printed on the label. An image of the product can also be printed on the label as disclosed in U.S. Patent Application No. (Stephenson shelf tag with image application), which is incorporated herein by reference. 
     Referring to  FIG. 6 , a hand-held writing device  68  for writing information on the electronically writable display elements  15  includes a standard bar code/RFID transceiver hand-held terminal  65 , such as an Opticon Model PHL 2700™ (Opticon Inc., Orangeburg N.Y.) and a shelf tag writing head  70 , which includes a means of precisely locating the writing head  70  with respect to the support body  35  of the electronically writable tag  55 . The hand-held terminal includes a communication port  62 , such as a standard RS 232 port for communicating with a processing and control circuit in the hand-held terminal  65 . The hand-held terminal includes a plurality of operator interface buttons  66 , a main trigger switch  69 , and a display screen  71 . The functions of the interface buttons and trigger switch, and the information displayed on display screen are all programmable by a user. 
     Referring to  FIG. 7 , the back of the hand-held writing device  68  is shown. A plurality of contact pins  75  are arranged in the write head  70  to contact the contact strips  40  on support body  35  when the write head  70  is located over the shelf tag  55 . The hand-held terminal  65  includes a bar code scanner  92  and an RFID transceiver  93  (shown in  FIG. 10 ) having a scanning window  90  located in an opening  85  in the write head  70  for allowing the scanner to view the bar code  60  on the label  10 . An alignment feature, such as a precision opening  80  in the write head  70  is used to locate the write head about the support body  35  to precisely align the contact pins  75  to the conductive strips  40  on support body  35 . Detent bumps  98  are molded into the write head  70  and are adapted to snap into recesses  38  (see  FIG. 5 ) in support body  35  to ensure proper engagement. The use of an RFID transceiver allows the option of reading of a Universal Product Code Identification Number without having to precisely aim the hand-held terminal as one has to when using the bar code scanner feature. Also the RFID transponder allows other programmable information to be stored locally on the display tag assembly  55 . The RFID label receives all wireless communication and power from the hand-held terminal. 
     An electrical feature, such as an electrical conductor  17  (see  FIG. 1 ) is provided on the in the display tag assembly  55  that can be sensed to determine that the write head is properly aligned with the display tag assembly  55  can also be provided. Sensor pins  95  may be provided in the write head to make contact with the conductor  17  to provide feedback to indicate to a user that the write head is properly aligned with the tag. The indication may be provided via the display screen  71 . Alternatively, an indicator  120  (see  FIG. 6 ) may be provided on the write head  70 . This indicator may emit sound or light to indicate that proper alignment is achieved. 
     Referring to  FIG. 8 , a partial cross sectional view of the hand-held terminal  65 , the write head  70 , and the tag  55  shows the write head  70  located in writing position over electronically writable tag  55 . The indicator  120  provides a visual or audible response when sensor pins  95  are in contact with the conductor  17  in display tag assembly  55 . 
     The hand-held writing device  68  can be manufactured as a single unit, or as shown in  FIG. 9  it can comprise a standard commercially available hand-held terminal  65 , and an attachable write head  70 . The write head  70  is provided with a circuit board with drive electronics  100 , power cable  105 , communication cable  115 , a plurality of contact pins  75 , wiring  110  for pins  75 , and a mechanical attachment interface  72  for releasably attaching the write head  70  to the hand-held terminal  65 . 
     Referring to  FIG. 10  the hand-held writing device includes a central processing and control circuit  130 , operator interface  66 ,  69 , a display  71 , a power supply  125 , a bar code scanner  92 , an RFID transceiver  93 , and drive electronics  100  for the write head. For the embodiment where the write head  70  is an attachment to an off the shelf hand-held terminal  65 , the location of the components is indicated by dashed lines. 
     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 
                 label 
               
               
                 15 
                 display element 
               
               
                 17 
                 electrical conductor 
               
               
                 18 
                 perforated window 
               
               
                 20 
                 character elements 
               
               
                 22 
                 conductive pads 
               
               
                 25 
                 printable surface 
               
               
                 30 
                 adhesive backing 
               
               
                 35 
                 support body 
               
               
                 38 
                 detent recess 
               
               
                 40 
                 conductive strips 
               
               
                 42 
                 conductive adhesive strips 
               
               
                 45 
                 recess in support body 
               
               
                 46 
                 recess in support body 
               
               
                 47 
                 RFID transponder 
               
               
                 48 
                 backer liner 
               
               
                 50 
                 display recess 
               
               
                 55 
                 display tag assembly 
               
               
                 60 
                 UPC printed bar code 
               
               
                 62 
                 communication port 
               
               
                 65 
                 hand-held terminal 
               
               
                 66 
                 input buttons 
               
               
                 68 
                 hand-held writing device 
               
               
                 69 
                 main trigger button 
               
               
                 70 
                 write head 
               
               
                 71 
                 display screen 
               
               
                 72 
                 mechanical attachment interface 
               
               
                 75 
                 contact pins 
               
               
                 80 
                 precision opening 
               
               
                 85 
                 opening for scanner 
               
               
                 90 
                 scanning window 
               
               
                 92 
                 bar code scanner 
               
               
                 93 
                 RFID transceiver 
               
               
                 95 
                 sensor pins 
               
               
                 98 
                 detent bumps 
               
               
                 100 
                 circuit board with drive electronics 
               
               
                 105 
                 power cable 
               
               
                 110 
                 wiring to pins 
               
               
                 115 
                 communications cable 
               
               
                 120 
                 indicator 
               
               
                 125 
                 power supply 
               
               
                 130 
                 processing and control circuit