TOUCH SENSITIVE DEVICE EMPLOYING BENDING WAVE VIBRATION SENSING AND EXCITATION TRANSDUCERS
First Claim
1. A touch sensitive apparatus, comprising:
- a touch plate;
a plurality of sensors coupled to the touch plate, each of the sensors configured to sense bending waves in the touch plate;
an excitation transducer coupled to the touch plate and configured to induce bending waves in the touch plate;
a plurality of active buffer circuits, each of the active buffer circuits respectively coupled to one of the sensors; and
a controller coupled to the sensors via the active buffer circuits and to the excitation transducer via a non-actively buffered connection, the controller configured to compute information related to a touch on the touch plate responsive to sense signals received by the sensors.
0 Assignments
0 Petitions
Accused Products
Abstract
A touch sensitive apparatus includes a touch plate to which several pickup sensors and at least one excitation transducer are coupled. Each of the sensors is configured to sense bending waves in the touch plate, and the excitation transducer is configured to induce bending waves in the touch plate. The apparatus may further include active buffer circuits, wherein each of the active buffer circuits is coupled to one of the sensors. A controller is coupled to the sensors via the active buffer circuits and to the excitation transducer via a non-actively buffered connection. The controller is configured to compute a location of a contact on the touch plate responsive to sense signals received from the sensors. The apparatus may be used to perform a variety of calibrations, including touch plate and sensor calibrations. Changes in touch sensing apparatus calibration and performance may be detected and tracked over time.
-
Citations
28 Claims
-
1. A touch sensitive apparatus, comprising:
-
a touch plate; a plurality of sensors coupled to the touch plate, each of the sensors configured to sense bending waves in the touch plate; an excitation transducer coupled to the touch plate and configured to induce bending waves in the touch plate; a plurality of active buffer circuits, each of the active buffer circuits respectively coupled to one of the sensors; and a controller coupled to the sensors via the active buffer circuits and to the excitation transducer via a non-actively buffered connection, the controller configured to compute information related to a touch on the touch plate responsive to sense signals received by the sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
28. A method for use with a touch sensitive device comprising a touch plate to which an excitation transducer and a plurality of sensors are respectively coupled, the method comprising:
-
applying an excitation signal generated by the excitation transducer to the touch plate and sensing the excitation signal by each of the sensors; determining a transfer function of an input at the excitation transducer to an output at each of the sensors; determining, for each of the sensors, a dispersion corrected impulse response using the transfer function; and performing a calibration of the touch sensitive device using the respective dispersion corrected impulse responses.
-
Specification