Touch sensor
AssigneeNXP B.V.
InventorsThomas Suwald, Arne Burghardt
Life of this patent
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Abstract
It is disclosed a touch sensor (100,200,300,400,500,700) for sensing a user touch, comprising an electrically conductive structure (101) having an electrically conductive touch area (103) exposed to the environment; a first capacitor (115) having a first electrode (117) electrically connected with the conductive structure (101); a second capacitor (119) having a first electrode (121) connected to a second electrode (123) of the first capacitor (115); and a driver arrangement (125) connected to the first capacitor and the second capacitor and adapted to perform particular operation steps.
Claims15
Touch sensor for sensing a user touch, comprising:
- an electrically conductive structure having an electrically conductive touch area exposed to the environment;
- a first capacitor having a first electrode electrically connected with the conductive structure
- a second capacitor having a first electrode connected to a second electrode of the first capacitor;
- and
- a driver arrangement connected to the first capacitor and the second capacitor and adapted to perform the operation steps:
- to supply a driving signal to the first capacitor to charge the first capacitor,
- to stop supplying the driving signal to the first capacitor, allowing a charge state of the first capacitor to be influenced by an object electrically contacting the touch area;
- to transfer a charge of the first capacitor to the second capacitor;
- and
- to measure the charge state of the second capacitor.
Method for sensing a user touch, comprising:
- supplying a driving signal to a first capacitor to charge the first capacitor, the first capacitor having a first electrode electrically connected with a conductive structure;
- stopping supplying the driving signal to the first capacitor,
- touching an electrically conductive touch area exposed to the environment with a finger, the touch area being part of the conductive structure;
- allowing a charge state of the first capacitor to be influenced by the finger touching the touch area;
- transferring a charge of the first capacitor to a second capacitor having a first electrode connected to a second electrode of the first capacitor, and
- measuring the charge state of the second capacitor;
- the method in particular further comprising:
- indicating a user touch event, if the charge state of the second capacitor reaches or supersedes a charge state threshold.
Dependencies are inferred from the claim text.