The present invention relates generally to electrically illuminated display systems. More particularly, the present invention relates to display systems and a power clamp for use therewith, the power clamp providing a safe and efficient method of removably securing and releasing a flexible printed circuit or illuminated graphics panel to a display system without requiring hard wiring of the panel to the display system, the printed circuit board or power source.
Merchandising systems, product displays and point of purchase retail display systems can take various forms, including shelf-mounted signs, hanging posters and brochure or literature display fixtures. Since an estimated 70% of purchase decisions are made within the retail store itself, effective merchandising displays can have a dramatic impact on sales for a particular product category or brand. Recently, conventional posters and signs have given way to electronic, dynamic display systems that present targeted product information as well as artwork or graphics to attract the attention of consumers. These electronic display systems typically incorporate illuminated posters, panels, screens or walls such as those containing light emitting diodes (LED), liquid crystal display screens, plasma screens or other illuminated components.
Of particular interest in display systems are electronically illuminated graphics panels, such as electroluminescent panels or lighting incorporating one or more phosphor layers or those including electrically functional inks printed on to a flexible substrate. Illuminated graphics panels are thin and flexible, making them easy to manufacture and install, and particularly advantageous where space in a showroom, lobby or retail environment is limited. Typically, an illuminated graphics panel comprises a flexible printed circuit which provides the electrical connection to the electroluminescent panel or illuminated graphics display, while not adding to the size, and in particular, the weight or thickness of the display panel.
However, illuminated graphics panels and display systems that incorporate flexible printed circuits must be secured to a power source by soldering, plug and socket assemblies, receptacle/clamping assemblies or otherwise permanently securing the electrical contacts or terminals on the flexible printed circuit to those of the power source, rigid circuit board or electrical connector. Several of these types of connectors are found in the prior art, such as U.S. Pat. No. 6,960,094 to Tomonari et al., which requires soldering of the connector to both the flexible printed circuit and the printed circuit board. U.S. Pat. No. 7,033,208 to Huang et al. describes a receptacle-type connector, in which each flexible printed circuit is permanently anchored within a receptacle to ensure a proper connection between the circuits. U.S. Pat. No. 6,869,291 to Norland et al. utilizes a connector including nonconductive elastomeric pads that urge the contacts of a flexible printed circuit into engagement with the contacts on a printed circuit board; however, sufficient connection is not made without rigidly fastening the printed circuit board to the flexible printed circuit.
Hard wiring or soldering of the flexible printed circuit contacts to a power source can introduce contaminants or scratches on the contacts, resulting in an incomplete or ineffective electrical connection, causing shorting within the system. Where machine screws or permanent clamps are used in place of soldering, such mechanisms conventionally require physical, permanent attachment of the FPC to the printed circuit, proper alignment, and such compressive force can cause damage to the contacts on the FPC.
In addition, due to the limited space and size of the electrical connections on a flexible printed circuit panel, the area for soldering is small and difficult to perform, which may also result in an incomplete or ineffective electrical connection.
Even when an adequate permanent connection is made, removal of the illuminated graphics panel from the power source damages the electrical contacts on the flexible printed circuit, therefore destroying the illuminated panel and requiring replacement of the contacts on the connector, circuit board or power source.
Accordingly, a need exists for a display system and electrical connector that provides power transfer capability between the electronically illuminated graphics panel and a power source, such as a circuit board or connection cable, without requiring hard wiring or soldering of the flexible printed circuit contacts to the source. In addition, there exists a need for a display system including a flexible printed circuit connector that is designed for multiple open/close cycles without damaging the graphics panel and/or the contacts on the connector or power source.