Accelerometer module for use with a touch sensitive device
View Patent ↗An accelerometer module for use with a touch sensor on a device, a method of detecting acceleration using a touch sensor, and a computer program product for receiving the touch sensor data and producing output representative of acceleration. The accelerometer module provides a device with a touch sensor, such as a mobile phone, with the ability to sense acceleration, orientation, or both. The accelerometer module may sense acceleration along a single axis or multiple axis. Sensing acceleration along three axis may be useful for producing a handheld game controller or for providing input to many other applications. The accelerometer module applies a force against a deformable member to change the contact area between the deformable member and the touch sensor, wherein the contact area is a function of the amount of applied acceleration.
1. A method of sensing acceleration, comprising:
disposing a deformable member adjacent a touch screen surface;
directing an acceleration to push the deformable member against the touch screen surface to cause a change in a degree of elastic deformation of the deformable member; and
sensing a change in a contact area between the deformable member and the touch screen surface as a result of the change in the degree of elastic deformation.
2. The method of claim 1 , further comprising:
applying a substantially constant biasing force to push the deformable member against the touch screen surface to cause a first extent of elastic deformation of the deformable member; and
directing an acceleration to oppose the substantially constant biasing force and result in a second extent of elastic deformation of the deformable member that is less than the first extent of elastic deformation.
3. The method of claim 2 , further comprising:
physically limiting the acceleration that is directed to push the deformable member against the touch screen to be an acceleration along a defined axis; and
identifying the direction of the acceleration along the defined axis by determining whether the contact area increased or decreased.
4. The method of claim 3 , further comprising:
identifying the relative magnitude of the acceleration by determining the extent of the change in the contact area.
5. The method of claim 4 , wherein the step of identifying the relative magnitude of the acceleration by determining the extent of the change in the contact area, includes using a correlation between contact area and acceleration.
6. The method of claim 5 , further comprising:
combining the direction and relative magnitude of the acceleration along each of three coordinate axis in order to determine the direction and relative magnitude of an overall acceleration.