Contact sensitive device

• US 8,274,480 B2
• Filed: 07/03/2002
• Issued: 09/25/2012
• Est. Priority Date: 07/04/2001
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: New Transducers Limited (Alphabet Inc.)
• Inventors: Sullivan, Darius Martin
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): CHOWDHURY, AFROZA Y
• Application Number:
  US10/482,865
• Publication Number:
  US 20040160421A1
• Time in Patent Office: 3,737 Days
• Field of Search: 345/173, 345/177, 345/178
• US Class Current: 345/173
• CPC Class Codes: G06F 3/043 using propagating acoustic waves
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A contact sensitive device (10) comprising a member (12) capable of supporting bending waves, a first sensor (16) mounted on the member for measuring bending wave vibration in the member, the sensor (16) determining a first measured bending wave signal and a processor which calculates information relating to a contact on the member (12) from the measured bending wave signal, the processor applying a correction based on the dispersion relation of the material of the member (12) supporting the bending waves, characterized in that the device (10) comprises a second sensor (16) to determine a second measured bending wave signal which is measured simultaneously with the first measured bending wave signal and the processor calculates a dispersion corrected function of the two measured bending wave signals which is selected from the group consisting of a dispersion corrected correlation function, a dispersion corrected convolution function, a dispersion corrected coherence function and other phase equivalent functions to determine information relating to the contact.

Claims

1. A contact sensitive device comprising a member capable of supporting bending waves, a first sensor mounted on the member for measuring bending wave vibration in the member, the sensor determining a measured bending wave signal and a processor which calculates information relating to a contact on the member from the measured bending wave signal, the processor applying a correction based on the dispersion relation of the material of the member supporting the bending waves, and wherein the processor calculates a dispersion corrected function, wherein the calculated dispersion corrected function is an autocorrelation function.

2. A contact sensitive device comprising:

a member capable of supporting bending waves,

a first sensor mounted on the member for measuring bending wave vibration in the member, the first sensor determining a first measured bending wave signal,

a processor which calculates information relating to a contact on the member from the measured bending wave signal, the processor applying a correction based on a dispersion relation of the material of the member supporting the bending waves,

wherein the device comprises a second sensor to determine a second measured bending wave signal which is measured simultaneously with the first measured bending wave signal and the processor calculates a dispersion corrected function of the two measured bending wave signals, the dispersion corrected function being selected from a group consisting of a dispersion corrected correlation function and a phase equivalent function to the dispersion corrected correlation function, to determine information relating to the contact; and

absorbers mounted around at least part of the periphery of the member to absorb reflected waves.