Patent Abstract:
A cover plate ( 5 ) for use with an electrical supply. In one embodiment, the backlit cover plate comprises a plate ( 5 ), the plate ( 5 ) including a window ( 15 ) therein; and backlighting, the backlighting powered by the electrical supply ( 55 ), the backlighting ( 20 ) disposed to be mounted on the plate ( 5 ) so as to shine through the window ( 15 ). Optional labels ( 45 ) may be provided through which the backlighting may shine, thereby illuminating data on the labels ( 45 ) from behind. In a disclosed embodiment, the backlighting ( 20 ) comprises electroluminescent lighting.

Full Description:
RELATED APPLICATIONS  
       [0001]     Applicant claims priority to Provisional Application No. 60/355,443, filed Feb. 7, 2002 in the United States Patent and Trademark Office. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This application relates generally to the field of electrical fixtures, and more specifically to backlighting for electrical cover plates and embodiments of same using techniques such as electroluminescence.  
       BACKGROUND OF THE INVENTION  
       [0003]     In both homes and commercial establishments, cover plates are conventionally attached to the walls or other surfaces to cover the electrical connections of switches and power outlets. Securing of the cover plate is well known in the art. Typically, the cover plate is secured to the receiving surface by two screws. In an example of a light switch, as is well known, a light is typically turned on and off by flipping the light switch in the appropriate on or off position. It is common for several switches to be located in one general region, such as a door. In order to visually identify which light is turned on or off by a certain light switch, a stick-on label such as a “Dymo” label may need to be affixed to the cover plate identifying the particular light controlled by that light switch. Further, if a light is not working when the controlling light switch is in the on position, a problem is presented because a person entering a darkened space cannot visually identify whether the problem is the light bulb or the circuit connected to the light switch. The light bulb must be changed to determine if the problem is the light bulb. If the light still does not work after changing the light bulb, the breaker must be checked to determine whether electricity is being supplied to the light switch. If the breaker has not interrupted the flow of electricity to the light switch, one may not be able to determine whether the source of the problem is the light switch or the light without further inquiry.  
         [0004]     With a power outlet, typically a power cord of an electrical device is plugged into one of the outlets of the power outlet through openings in the wall plate. Through this connection, electricity is supplied to the electrical device. If the electrical device is not operating when turned on, a problem is presented because one cannot visually identify whether the electrical device is malfunctioning or the electrical circuit at the power outlet is not providing electricity. Typically, one tests the power outlet or the electrical device to determine the source of the problem. In addition, a person may not be able to visually identify at the power outlet which electrical device is plugged into a particular outlet. Typically, one follows the power cord to the particular electrical device. The person may also affix a label to the wall plate identifying the particular electrical device.  
       SUMMARY OF THE INVENTION  
       [0005]     A backlit cover plate for use with an electrical supply addresses these and other needs in the art. The backlit cover plate comprises a plate, the plate including a window therein, and backlighting powered by the electrical supply, the backlighting disposed to be mounted on the plate so as to shine through the window. The backlit cover plate may optionally further comprise a switch on the electrical supply, the switch having an operating mechanism to alternatively connect or interrupt the electrical supply, the plate further comprising an opening, the operating mechanism of the switch receivable in the opening, the backlighting connected to the power supply so as to be energized when the switch interrupts the power supply. In addition, the backlit cover plate may optionally further comprise a label, the label including a translucent background and an opaque foreground comprising data to be communicated, the label disposed to be mounted so that the backlighting shines through the window and the label. It will be seen that a technical advantage of the invention includes backlighting a portion of a cover plate, addressing some of the problems encountered by conventional cover plates. For instance, embodiments of the invention allow visual monitoring of an electrical circuit at a light switch or power outlet.  
         [0006]     Further technical advantages include visual identification of light switches and power outlets, which, especially in conjunction with a backlit label, assists an individual in not turning on the wrong light or plugging an appliance into the wrong power outlet by mistake. When in use with a power outlet, a further technical advantage includes freeing up all available outlets of a power outlet, without using up one outlet to illuminate the cover plate itself. The invention also allows an individual to use the proper light switch or power outlet when lighting is poor, which enhances convenience and improves safety to the individual. The invention further allows different colors to be used for the backlighting, which allows an individual to use the invention for aesthetics or color coding. Although the invention is conveniently embodied on a cover plate for use with standard household AC electrical supply, the invention is not limited. In this regard, it will be appreciated that other embodiments are possible for any type of power supply in any environment. Note also that the invention is not limited to AC embodiments. Although the invention is described herein with respect to embodiments using electroluminescence for backlighting powered by AC supply, it will be seen that the principles of the invention apply with equivalent enabling effect to embodiments relying on DC power supply. The foregoing has outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:  
         [0008]      FIG. 1  illustrates an embodiment of the invention showing a switch cover plate with electroluminescent backlighting.  
         [0009]      FIG. 2  is a plane view of the embodiment of switch cover plate invention illustrated from the reverse side of  FIG. 1 .  
         [0010]      FIG. 3  illustrates another embodiment of the invention showing an outlet cover plate with electroluminescent backlighting.  
         [0011]      FIG. 4  is a plane view of the embodiment of the outlet cover plate of  FIG. 3  from the reverse side.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     An embodiment of the invention is described with respect to  FIG. 1 , in which a backlit cover plate  5  comprises a plate  10 , a window cover  15 , which cover engages the edges of the window  30  thereby permitting the electroluminescent (EL) backlighting  20 , more clearly shown in  FIG. 2 , to emit light through the window  30 . Label  45 , which displays either text or symbols, is positioned between the EL backlighting  20  and window cover  15  is thereby contrasted and highlighted. Plate  10  has a switch opening  25 , a window  30 , and at least one plate-securing opening  35 . As shown, screws, nails or any other suitable fasteners may be used to secure the plate  10  to a surface through plate-securing openings  35 . As previously noted, window  30  is an opening in plate  10 , but may also be formed with transparent material (not shown) in lieu of window cover  15 . The contrasting text or symbols on label  45  would then be attached to the top of the backlit window  30  without departing from the spirit or intent of the invention.  
         [0013]     In the embodiment illustrated in  FIG. 1 , label  45  containing either text or symbols or both, can be mounted within window  30 . Label  45  comprises a foreground and a background. Label  45  is secured within the window  30  by glue, snap fitting, or any other suitable securing method. The background of the label  45  is advantageously comprised of any semirigid, translucent material, preferably clear plastic. The foreground comprises data to be communicated. A variety of lettered or numbered labels known in the art may be used for the data, but preferably individual letters or numbers that have adhesive backing may be used. The opaque letters or numbers in such embodiments are affixed to the background. Window cover  15  covers window  30  and label  45 . Window cover  15  is secured to plate  10  by snap fitting within the interior edges of window  30  or any other suitable securing method. Window cover  15  is also comprised of any semi-rigid, translucent material, preferably clear plastic.  
         [0014]      FIG. 2  is an plane view of the embodiment of the invention shown on  FIG. 1  from the reverse side more clearly disclosing the disposition of the EL backlighting  20 .  FIG. 2  illustrates the backlit cover plate  5  having a back plate  50 . As shown, EL backlight  20  is secured to plate  10  on the backside of the window  30 . EL backlight  20  is secured to the plate  10  by snap fitting, glue, or any other suitable securing method. The materials to form EL backlight  20  are well known in the art. Examples of available electroluminescent materials which can be used for backlight  20  include Durel A3, NEC, and Indiglo. EL backlight  20  illuminates plate  10 , window  30 , and label  45  and provides at least two EL electrodes  55  through which a potential across the phosphor is provided to illuminate the EL backlight  20 , all in a manner well known in the art. A back plate (not shown) can be fashioned to enclose EL backlight  20  and secured to the back side of plate  10 , although is not required. This back plate can be secured to plate  10  by glue, snap fitting, or any other suitable securing methods. Alternatively, the electroluminescent material could be molded into the plate  10  and provide a recessed area or window to allow text or symbols to be inserted in the recess or window without departing from the scope of the disclosure contained herein. The backlighting color can be varied by an appropriate choice of phosphor materials, in a manner well known in the industry to provide a variety of colors or hues. Additionally, the backlighting may be accomplished with the use of light emitting diodes (LEDs) which are readily available in the marketplace and which are well known in the industry.  
         [0015]     The following describes an exemplary application of the present invention as embodied and illustrated on  FIGS. 1 and 2 . In operation, connectors  55  are connected to a power source at a light switch on a wall. The light switch controls a light. The power source at the light switch forms an electrical circuit with the light. Plate  10  is then secured to the wall at the light switch. Plate  10  is disposed to enable a light switch to pass through switch opening  25 . Screws are inserted through the plate securing openings  35  and are used to secure plate  10  to the light switch and the wall. Through the connectors  55 , electricity from the power source flows through the back plate electrodes and to the opposed plates sandwiching the phosphor of the backlight  20 . The light switch controls the flow of electricity to the light and EL backlight  20 . When the light switch is in the off position, EL backlight  20  is energized, while the electrical circuit to the light is interrupted. The line voltage from the electrical power source potentiates EL backlight  20  via the connectors  55 . The light switch is then visually identifiable in the dark via the EL backlighting  20 .  
         [0016]     When the light switch is in the on position, the electrical circuit to the light is connected, and electricity flows directly to the light, which becomes illuminated. EL backlight  20  is no longer illuminated. If the light does not illuminate when the light switch is turned to the on position, the electrical circuit at the light switch may be checked by viewing backlit cover plate  5 . If EL backlight  20  illuminates when the switch is in the off position, voltage is present across EL backlight  20  and the electrical circuit from the power source is functioning properly, and one may conclude the light bulb or light is not functioning properly. The light bulb may then be replaced or the light may be serviced. If EL backlight  20  does not illuminate, no voltage has reached the EL backlight  20  and the electrical circuit at the power source is not functioning properly, which signifies, from an absence of electrical power at the appropriate outlet, that the light switch or power supply may need service.  
         [0017]     To identify which particular light the switch controls, window cover  15  may be removed from the plate  10 , and label  45  may be mounted within the window  30 . The foreground data may be affixed to the background of label  45  in any word, number, or symbol order that identifies the particular light. Window cover  15  is then secured again to plate  10 . Label  45  can visually identify the light corresponding to the light switch at all times. When the light switch is turned to the on position, the illumination provided by the light allows a person to view the label  45  and identify the light. When the light switch is turned to the off position and no other external light is available, the illumination of EL backlight  20  illuminates label  45  and allows one to clearly view label  45 , which can be fabricated from a variety of colors or hues as previously noted.  
         [0018]     Even though the above disclosure describes the backlit cover plate  5  in assembled form, backlit cover plate  5  is also available disassembled (not illustrated), with the following components disassembled from the backlit cover plate  5 , plate  10 , EL backlight  20 , label  45 , and window cover  15 . In addition, the disassembled components of the backlit cover plate  5  may be packaged together in a kit (not illustrated). The kit may be in any form that is packaged together and available to a consumer.  
         [0019]     Even though the above disclosure describes incorporating EL backlight  20  into a light switch plate, the present invention is expressly not limited to such applications, and may be useful in various other applications. The present invention would prove useful in illuminating and identifying power outlets, telephone jacks, and internet jacks.  
         [0020]     For example,  FIG. 3  discloses another embodiment of the present invention for an electrical outlet plate. Plate  10  is formed from molded plastic in a manner well known to the industry and provides an opening  35  for attaching such plate to an electrical junction box mounted in a wall, all in a manner well known to the electrical trades. The outlet plate of  FIG. 3  also provides a window  30 , through which text or symbols  45  may be viewed, covered with window cover  15 , all as previously described in the description of  FIGS. 1 and 2  above. Plate  10  of  FIG. 3  provides additional openings  26  for standard electrical receptacles.  
         [0021]      FIG. 4  discloses the reverse of outlet cover plate  10  of  FIG. 3 .  FIG. 4  further discloses the EL backlight  20  connected to two conductors  65  which provided clips  66  for connection to the electrical service provided to the outlet junction box previously described. A person skilled in the electrical trades can easily substitute any number of available electrical connectors to the conductors which provide the potential to the EL backlight  20  and still remain within the scope of the disclosure made herein. Further, the conductors to the EL backlight can provide appropriate fusing to prevent shortcircuiting of EL backlight  20 . When the backligting is on, the outlet is shown to be provided with electrical service. If the backlighting is off, the electrical service to the outlet has been interrupted and one can readily determine the cause of the absence of the service at the outlet.  
         [0022]     The present invention is further not limited to use in electrical outlets disposed in walls. The invention is further not limited to use of electroluminescence for backlighting. Other types of backlighting are known in the art, such as conventional filament lighting or light emitting diodes. It will be further appreciated that the invention may incorporate backlighting into a power plate in any technology or application calling for such functionality.  
         [0023]     As described above in the summary sections, it will also be understood that the embodiments are possible covering structures or surfaces other than walls. Further, it will be appreciated that the invention is not limited to embodiments working off AC supply. The invention is equally enabled by embodiments working off DC supply. Any application which specifies the application of an electric field to a dielectric phosphor to release light in a switch or outlet plate for identification of the switch or outlet may be accomplished by the present disclosure.  
         [0024]     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Technology Classification (CPC): 7