Keypad with integrated touch sensitive apparatus
View Patent ↗A touch sensitive keypad device ( 101 ) for an electronic device ( 100 ) includes one or more keys ( 106,107,108,109,110 ) situated in a keypad carrier ( 206 ). One or more conductive layers ( 115,116,117,118 ) span the keys. One or more transverse conductive layers ( 119,120,121,122,123,124 ) are integrated with a non-key component, such as the keypad carrier ( 205 ). A capacitance sensing circuit ( 126 ) detects changes in capacitance between the conductive layers and the transverse conductive layers to detect user input, thereby allowing a user ( 1990 ) to use a matrix ( 1902 ) of keys as a touch pad.
1. A touch sensitive apparatus for an electronic device, comprising:
one or more keys of a keypad situated on a keypad carrier and configured for movement within the keypad structure;
a conductive layer integrated with the one or more keys;
a transverse conductive layer integrated with a non-key component and electrically isolated from the conductive layer;
an intermediate conductive layer electrically isolated from the conductive later and the transverse conductive layer;
a substrate; and
one or more actuators disposed between the none-key component and the substrate;
wherein an electrical capacitance defined between the conductive layer and the transverse conductive layer is configured to change when a conductive object is proximately located with the conductive layer; and
at least one actuator is to compress in response to an actuation force applied to at least one corresponding key.
2. The touch sensitive apparatus of claim 1 , wherein the conductive layer comprises an electrically conductive coating disposed one of:
above; or
beneath;
the one or more keys.
3. The touch sensitive apparatus of claim 1 , wherein the conductive layer comprises a conductive film molded into a body of the one or more keys.
4. The touch sensitive apparatus of claim 1 , wherein the one or more keys are coupled together by a translucent, conductive adhesive.
5. The touch sensitive apparatus of claim 1 , wherein the conductive layer comprises at least one of conductive paint disposed above the one or more keys, indium tin oxide disposed above the one or more keys, a metallic coating disposed above the one or more keys, a conductive polymer disposed above the one or more keys, poly(3,4-ethylenedioxythiophene) disposed above the one or more keys, conductive paint disposed beneath the one or more keys, indium tin oxide disposed beneath the one or more keys, a metallic coating disposed beneath the one or more keys, a conductive polymer disposed beneath the one or more keys, poly(3,4-ethylenedioxythiophene) disposed beneath the one or more keys, or combinations thereof.
6. The touch sensitive apparatus of claim 1 , further comprising:
an electromagnetic source coupled to the conductive layer, resulting in an electrical potential being defined between the conductive layer and the transverse conductive layer; and
further comprising a capacitance detection circuit, operable with the conductive layer to detect the change in the electrical capacitance when the conductive object is proximately located with the conductive layer.
7. The touch sensitive apparatus of claim 1 , wherein the non-key component comprises one or more of:
a substrate, a light guide, a flexible layer, a key carrier, or a housing.
8. The touch sensitive apparatus of claim 1 ,
wherein the electrical capacitance defined between the conductive layer and the transverse conductive layer is defined from the conductive layer to the intermediate conductive layer to the transverse conductive layer.
9. The touch sensitive apparatus of claim 1 , wherein a body of each of the one or more keys is manufactured from conductive material.
10. The touch sensitive apparatus of claim 1 , wherein the conductive layer comprises a plurality of conductive layer segments, each of the plurality of conductive layer segments being coupled to an adjacent conductive layer segment by a conductive bridge contact.
11. The touch sensitive apparatus of claim 1 , wherein the conductive layer further comprises an electrically conductive coating disposed above the one or more keys.