Write head for a display tag having a liquid crystal display

A system for displaying information on display tags, comprising:

• a) a display tag having a printable label, a bar code printed on the label, a bistable liquid crystal display mounted on the label, and a plurality of electrical contact pads connected to a corresponding plurality of electrodes in the display;
• b) a display tag programming device including:
• i) a hand held scanner unit having control electronics, a bar code scanner connected to the control electronics, a database containing display commands associated with bar codes on display tags, a user interface connected to the control electronics including a display and a button for activating the scanner, and
• ii) a display tag writing head connected to the hand held scanner unit for changing the display state of a liquid crystal display on a display tag, including a body defining a slot for receiving and locating the display tag with respect to the body, a plurality of contact pins located in the body and being mounted for movement into the slot to contact the electrical contact pads of a display tag located in the slot, drive electronics electrically connected to the contact pins for receiving display command signals from an external source and for applying electrical drive signals to the electrodes of the display when the contact pins are in contact with the electrical contact pads, and operator control means for moving the contact pins into electrical contact with the electrical contact pads and causing the drive electronics to apply the electrical drive signals to the contact pins;
• and
• c) a central computer for generating display commands associated with bar codes;
• the central computer including means for transferring the display commands to the memory of the hand held scanner unit.