Capacitive touch screen
The present invention provides a capacitive touch screen ( 1 ) which includes a substrate ( 10 ), a first electrode plate ( 20 ), an elastic spacer ( 30 ), a second electrode plate ( 40 ) and a transparent panel ( 50 ). The substrate ( 10 ) is made of a plate having a rim ( 11 ). The first electrode plate ( 20 ) is placed on the rim ( 11 ) of the substrate ( 10 ). The elastic spacer ( 30 ) is interposed between the first electrode plate ( 20 ) and second electrode plate ( 40 ). One of the first and second electrode plates comprises four or more electrode plates arranged along the rim ( 11 ) of the substrate ( 10 ). When a pressure is applied to the transparent panel ( 50 ), a distance (d) between the first and second electrode plate changes. Thereby, capacitances are varied at sensing points (S) corresponding to locations of the four or more electrode plates, and a touch location and a touch pressure are determined by variation rates of the measured capacitances.
1. A capacitive touch screen, comprising:
a substrate ( 10 ) comprising a plate which is open in a central portion thereof other than a rim ( 11 ) or comprising a transparent solid plate;
a first electrode plate ( 20 ) placed on an upper surface of the rim ( 11 ) of the substrate ( 10 );
an elastic spacer ( 30 ) placed on an upper surface of the first electrode plate ( 20 ), the elastic spacer ( 30 ) being variable in thickness in response to application of an external pressure so as to be restorable to original shape thereof;
a second electrode plate ( 40 ) placed on an upper surface of the elastic spacer ( 30 ); and
a transparent panel ( 50 ) placed on an upper surface of the second electrode plate ( 40 ) to cover an entire area of the substrate ( 10 );
wherein one electrode plate of the first electrode plate ( 20 ) and the second electrode plate ( 40 ) comprises four or more electrode plates arranged along the rim ( 11 ) of the substrate ( 10 ) at positions spaced apart from each other at predetermined intervals, the other electrode plate comprises a single electrode plate arranged over the rim ( 11 ) along the overall length thereof; and
when a contact pressure is applied to a portion of the transparent panel ( 50 ), a distance (d) between the first electrode plate ( 20 ) and the second electrode plate ( 40 ) is restorably varied by elastic height variation of the elastic spacer ( 30 ), so that capacitances are varied at sensing points (S) corresponding to locations of the four or more electrode plates ( 20 ) or ( 40 ), and a touch location and a touch pressure are determined by variation rates of the capacitances measured at the sensing points (S).
2. A capacitive touch screen, comprising:
a substrate ( 10 ) comprising a plate which is open in a central portion thereof other than a rim ( 11 ) or comprising a transparent solid plate;
a first electrode plate ( 20 ) placed on an upper surface of the rim ( 11 ) of the substrate ( 10 );
an elastic spacer ( 30 ) placed on the upper surface of the rim ( 11 ) of the substrate ( 10 ), the elastic spacer ( 30 ) being variable in thickness in response to application of an external pressure so as to be restorable to original shape thereof;
a transparent panel ( 50 ) placed on an upper surface of the elastic spacer ( 30 ) to cover an entire area of the substrate ( 10 ); and
a second electrode plate ( 40 ) placed beneath a lower surface of the transparent panel ( 50 ) such that the second electrode plate ( 40 ) is spaced apart from the first electrode plate ( 20 ) by a predetermined distance;
wherein one electrode plate of the first electrode plate ( 20 ) and the second electrode plate ( 40 ) comprises four or more electrode plates arranged along the rim ( 11 ) of the substrate ( 10 ) at positions spaced apart from each other at predetermined intervals, the other electrode plate comprises a single electrode plate arranged over the rim ( 11 ) along the overall length thereof; and
when a contact pressure is applied to a portion of the transparent panel ( 50 ), a distance (d) between the first electrode plate ( 20 ) and the second electrode plate ( 40 ) is restorably varied by elastic height variation of the elastic spacer ( 30 ), so that capacitances are varied at sensing points (S) corresponding to locations of the four or more electrode plates ( 20 ) or ( 40 ), and a touch location and a touch pressure are determined by variation rates of the capacitances measured at the sensing points (S).
3. A capacitive touch screen, comprising:
a substrate ( 10 ) comprising a plate which is open in a central portion thereof other than a rim ( 11 ) or comprising a transparent solid plate;
a first elastic spacer ( 30 a ) placed on an upper surface of the rim ( 11 ) of the substrate ( 10 ), the first elastic spacer ( 30 a ) being variable in thickness in response to application of an external pressure so as to be restorable to original shape thereof;
a first electrode plate ( 20 ) placed on an upper surface of the first elastic spacer ( 30 a );
a second elastic spacer ( 30 b ) placed on an upper surface of the first electrode plate ( 20 ), the second elastic spacer ( 30 b ) being variable in thickness in response to application of external pressure so as to be restorable to original shape thereof;
a transparent panel ( 50 ) placed on an upper surface of the second elastic spacer ( 30 b ) to cover an entire area of the substrate ( 10 ); and
a pair of second electrode plates ( 40 ) respectively placed on the upper surface of the rim ( 11 ) of the substrate ( 10 ) and beneath a perimeter of a lower surface of the transparent panel ( 50 ) such that the second electrode plates ( 40 ) are spaced apart from the first electrode plate ( 20 ) by predetermined distances;
wherein one electrode plate of the first electrode plate ( 20 ) and the second electrode plate ( 40 ) comprises four or more electrode plates arranged along the rim ( 11 ) of the substrate ( 10 ) at positions spaced apart from each other at predetermined intervals, and the other electrode plate comprises a single electrode plate arranged over the rim ( 11 ) along the overall length thereof; and
when a contact pressure is applied to a portion of the transparent panel ( 50 ), a distance (d) between the first electrode plate ( 20 ) and the second electrode plate ( 40 ) is restorably varied by elastic height variation of the elastic spacers ( 30 a ) and ( 30 b ), so that capacitances are varied at sensing points (S) corresponding to locations of the four or more electrode plates ( 20 ) or ( 40 ), and a touch location and a touch pressure are determined by variation rates of the capacitances measured at the sensing points (S).
4. The capacitive touch screen according to claim 1 ,
wherein the elastic spacer ( 30 ) comprises an elastic synthetic resin member or a spring ( 30 c ) which varies in height in response to application of an external pressure so as to be restorable, or a hinge structure ( 30 d ) having restorability to be returned to an original state thereof.
5. The capacitive touch screen according to claim 2 ,
wherein the elastic spacer ( 30 ) comprises an elastic synthetic resin member or a spring ( 30 c ) which varies in height in response to application of an external pressure so as to be restorable, or a hinge structure ( 30 d ) having restorability to be returned to an original state thereof.
6. The capacitive touch screen according to claim 3 ,
wherein the elastic spacer ( 30 ) comprises an elastic synthetic resin member or a spring ( 30 c ) which varies in height in response to application of an external pressure so as to be restorable, or a hinge structure ( 30 d ) having restorability to be returned to an original state thereof.