EP 1108224 A2 20010620 - METHOD AND SYSTEM FOR MEASURING THE DISTANCE FROM A PIEZOELECTRIC ELEMENT
Title (en)
METHOD AND SYSTEM FOR MEASURING THE DISTANCE FROM A PIEZOELECTRIC ELEMENT
Title (de)
VERFAHREN UND SYSTEM ZUR MESSUNG DER ENTFERNUNG EINES PIEZOELEKTRISCHEN ELEMENTS
Title (fr)
PROCEDE ET SYSTEME PERMETTANT DE MESURER UNE DISTANCE DEPUIS UN ELEMENT PIEZO-ELECTRIQUE
Publication
Application
Priority
- IL 9900470 W 19990827
- US 9820398 P 19980827
Abstract (en)
[origin: WO0013039A2] A method and system for measuring the distance from a piezoelectric substance (10) by transmitting an electromagnetic pulse (14) to the piezoelectric substance so as to generate an acoustic pulse (15) in response thereto. The acoustic pulse is sensed by an acoustic sensor (12) displaced from the piezoelectric substance by an unknown distance, and a time interval between initiation of the electromagnetic pulse and receipt of the acoustic pulse is measured. The distance between the piezoelectric substance and the acoustic sensor is computed by multiplying the measured time interval by the speed of sound, which is known. Upon striking the piezoelectric surface against a surface a modified echo characteristic of the acoustic pulse may be detected. This allows operation of one of a plurality of switches to be detected. By using multiple sensors, the spatial location of the switch can be computed and this allows the specific switch to be identified in a computer keyboard adapted for use with a computer but not physically connected thereto.
IPC 1-7
IPC 8 full level
A63H 30/02 (2006.01); G01S 5/30 (2006.01); G01S 11/16 (2006.01); G01S 15/10 (2006.01); G01S 15/46 (2006.01); G06F 3/033 (2006.01); G06F 3/043 (2006.01); H01L 41/09 (2006.01)
CPC (source: EP)
G01S 5/30 (2013.01); G01S 11/16 (2013.01); G06F 3/0433 (2013.01)
Citation (search report)
See references of WO 0013039A2
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
WO 0013039 A2 20000309; WO 0013039 A3 20000608; AU 5441899 A 20000321; CA 2341907 A1 20000309; EP 1108224 A2 20010620; JP 2002525591 A 20020813
DOCDB simple family (application)
IL 9900470 W 19990827; AU 5441899 A 19990827; CA 2341907 A 19990827; EP 99940445 A 19990827; JP 2000571082 A 19990827