Domesheet assembly in a keyboard

Abstract

A domesheet assembly for use with a circuit board in a keyboard. The domesheet assembly has a dome-mounting sheet with a plurality of recesses separated by a plurality of bridging sections. A dome is attached to the upper part of a recess via a bead of glue so that only a small section of the dome is physically connected to the dome-mounting sheet. An air passage is provided between neighboring recesses through the bridging section so as to allow some of the air in a recess to escape to the neighboring recesses when a key is pressed. The dome-mounting sheet is securely attached to a printed wire board or printed circuit board by an adhesive to form a domesheet assembly. The domesheet assembly is hermetically sealed to prevent moisture from reaching under the domes.

1 . A domesheet assembly for use with a circuit board, comprising: 
 a dome-mounting sheet having a plurality of recesses separated by a plurality of bridging sections, each recess having a recess surface, the recess surface having a recess surface curvature; and    a plurality of domes, each dome having a first surface facing the recess surface and a second surface facing the circuit board, the first surface having a dome surface curvature smaller than the recess surface curvature, wherein the first surface has a top section connected to the recess surface of one of the recesses.    
   
   
       2 . The domesheet assembly of  claim 1 , wherein each of the recesses has at least an air escaping passageway connected to one or more adjacent recesses.  
   
   
       3 . The domesheet assembly of  claim 1 , wherein the top section of the first surface is securely attached to the corresponding recess by a layer of adhesive material.  
   
   
       4 . The domesheet assembly of  claim 1 , wherein the bridging sections are securely attached to the circuit board.  
   
   
       3 . The domesheet assembly of  claim 1 , wherein the adhesive material comprises a bead, separating the top section of the dome from the recess surface.  
   
   
       6 . The domesheet assembly of  claim 1 , wherein the circuit board has a plurality of electrically conductive segments under each recess, and wherein at least a part of each dome is electrically conductive so that when a dome is caused to make contact with the circuit board, at least two of the electrically conductive segments are electrically connected.  
   
   
       7 . A keyboard comprising: 
 a circuit board,    a domesheet assembly disposed over the circuit board;    a plurality of keys disposed over the domesheet assembly; and    an actuating sheet disposed between the keys and the domesheet, wherein the domesheet assembly comprises:    a dome-mounting sheet having a plurality of recesses separated by a plurality of bridging sections, each recess having a recess surface, the recess surface having a recess surface curvature; and    a plurality of domes, each dome having a first surface facing the recess surface and a second surface facing the circuit board, wherein the first surface has a dome surface curvature smaller than the recess surface curvature so that only a top section of the first surface is connected to the recess surface of one of the recesses.    
   
   
       8 . The keyboard of  claim 7 , wherein the top section of the first surface is connected to the recess surface by an adhesive material.  
   
   
       9 . The keyboard of  claim 7 , wherein the dome-mounting sheet further comprises a plurality of channels for providing air passageways between the recesses so as to allow air in the recesses to move between the recesses.  
   
   
       10 . The keyboard of  claim 7 , wherein the bridging sections are securely attached to the circuit board by an adhesive material.  
   
   
       11 . The keyboard of  claim 8 , wherein the adhesive material comprises a bead, separating the top section of the dome from the recess surface.  
   
   
       12 . The keyboard of  claim 7 , wherein the circuit board has a plurality of electrically conductive segments under each recess, and wherein at least a part of each dome is electrically conductive so that when a key is pressed to cause a dome to make contact with the circuit board, at least two of the electrically conductive segments are electrically connected.  
   
   
       13 . A method to improve tactility and protection of a keyboard, the keyboard comprising: 
 a circuit board,    a domesheet assembly disposed over the circuit board;    a plurality of keys disposed over the domesheet assembly; and    an actuating sheet disposed between the keys and the domesheet, wherein the domesheet assembly comprises:    a dome-mounting sheet having a plurality of recesses separated by a plurality of bridging sections, each recess having a recess surface, and    a plurality of domes, each dome having a first surface facing the recess surface and a second surface facing the circuit board, wherein the first surface has a dome surface curvature, said method comprising:    shaping the recess surface such that the recess surface curvature is greater than the dome surface curvature; and    securing the first surface of a dome to a part of the corresponding recess surface such that only a top section of the first surface is connected to the recess.    
   
   
       14 . The method of  claim 13 , wherein the top section of the first surface of the dome is connected to the recess by a bead of adhesive material so that when a key is pressed, the key causes a dome to make contact with the circuit board through the actuating sheet and through the bead.  
   
   
       15 . The method of  claim 13 , wherein the dome-mounting sheet further comprises a plurality of channels for providing air passageways between the recesses so as to allow air in the recesses to move between the recesses.