BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial exploded view of a backlighted membrane switch in accordance with the present invention as seen from the upper portion of one side thereof;
FIG. 2 is another partial exploded view of the backlighted membrane switch as seen from the front portion thereof;
FIG. 3 is a front plan schematic view of the backlighted membrane switch;
FIG. 4 is a partial cross sectional view of the backlighted membrane switch;
FIG. 5 is a partial exploded view of the backlighted membrane switch as seen from the front portion thereof, similar to FIG. 2, illustrating the other arrangement of the backlighted membrane switch; and
FIG. 6 is a further partial exploded view of the backlighted membrane switch as seen from the front portion thereof, similar to FIGS. 2 and 5, illustrating the further arrangement of the backlighted membrane switch.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and initially to FIGS. 1-3, a backlighted membrane switch 1 in accordance with the present invention comprises a base circuit board 10 to be disposed in an inner and bottom portion of a typical outer housing (not shown), the circuit board 10 includes one of the two sides, such as the upper side 11 having a printed circuit 12 applied or disposed or printed thereon and having a number of switch contacts 13 formed or provided thereon.
A soft or resilient spacer 20 is to be disposed or engaged onto the circuit board 10 and includes a number of openings 21 formed therein or provided therein and aligned with the switch contacts 13 of the printed circuit 12 of the circuit board 10 for allowing the switch contacts 13 to be partially engaged into the openings 21 of the soft or resilient spacer 20 (FIGS. 2-4). The soft or resilient spacer 20 may also be attached to or formed integral with the circuit board 10 as shown in FIG. 5.
The backlighted membrane switch 1 further includes a soft or resilient film or membrane or plate 30 to be disposed above the circuit board 10 or engaged onto the spacer 20 or arranged to have the spacer 20 disposed between the circuit board 10 and the plate 30, and includes a bottom portion 31 facing toward the circuit board 10 and having a number of conductor contacts 32 attached thereto or extended outwardly therefrom and aligned with the switch contacts 13 of the printed circuit 12 and also aligned with the openings 21 of the spacer 20 for allowing the conductor contacts 32 also to be partially engaged into the openings 21 of the soft or resilient spacer 20 (FIGS. 2-4).
The conductor contacts 32 of the plate 30 are also aligned with the keys or key pads 80 of the backlighted membrane switch 1 (FIG. 3) for being selectively depressed or stricken or forced to engage with the switch contacts 13 of the printed circuit 12 of the circuit board 10. The soft or resilient spacer 20 may thus be used and acted as a spacing means or device for suitably or resiliently spacing the conductor contacts 32 of the plate 30 from the switch contacts 13 of the printed circuit 12 of the circuit board 10 and for allowing the conductor contacts 32 of the plate 30 to be selectively forced to engage with the switch contacts 13 of the printed circuit 12 of the circuit board 10.
The plate 30 further includes an upper portion 33 having an electroluminescent member or device 34 attached thereto or applied thereon or integrated therein and made of such as illuminating or electroluminescent materials, and further includes a terminal 35 attached thereto or provided thereon and electrically coupled to the electroluminescent member or device 34 for allowing the electroluminescent member or device 34 to be selectively operated or energized or actuated to generate a backlight when an electric energy is supplied to the terminal 35 and then to the electroluminescent member or device 34. The electroluminescent member or device 34 may also be directly integrated into the plate 30.
For example, as best shown in FIG. 1, the electroluminescent device 34 may preferably include a number of dots or lighting areas 36 aligned with the conductor contacts 32 of the plate 30 and also aligned with the switch contacts 13 of the printed circuit 12 of the circuit board 10 and also aligned with the openings 21 of the spacer 20, and coupled together with conductor lines 37 for allowing the lighting areas 36 of the electroluminescent device 34 to be suitably energized or actuated to generate the backlight.
In operation, as shown in FIG. 3, the backlighted membrane switch 1 may be attached or engaged into an electric facility 8, such as a keyboard 8 which includes a number of keys or key pads 80 for aligning with the dots or lighting areas 36 of the electroluminescent device 34 and for allowing the lighting areas 36 of the electroluminescent device 34 to be suitably depressed or actuated with the keys or key pads 80 of the keyboard 8 or the electric facility 8.
It is to be noted that the electroluminescent device 34 includes a thin or greatly reduced thickness and weight as compared with the light devices of the typical backlighted membrane switches, and the electroluminescent device 34 may also be easily and quickly applied or disposed or printed onto or integrated into the plate 30 such that the manufacturing procedures may be greatly simplified and the manufacturing for the backlighted membrane switch 1 may also be suitably reduced.
As shown in FIG. 4, a sheath or covering 50 may further be provided and engaged onto the outer peripheral portion of the circuit board 10, the spacer 20, and the plate 30 for forming or making a liquid or fluid tight seal to the backlighted membrane switch 1 or for suitably sealing the circuit board 10 and the spacer 20 and the plate 30, and for preventing the circuit board 10 and the spacer 20 and the plate 30 from being wetted or damaged by humidity. As shown in FIG. 6, the soft or resilient spacer 20 may also be attached to or formed integral with the plate 30.
Accordingly, the backlighted membrane switch in accordance with the present invention includes a simplified structure for suitably reducing the weight and/or the thickness of the membrane switch, and for suitably reducing the manufacturing processes and the cost of the membrane switch.
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
Patent Application
20080036003
