Global patent index - EP 1012540 A1

EP 1012540 A1 2000-06-28 - OPTICAL TRANSDUCER, METHOD AND LASER DIODE ARRANGEMENT

Title (en)

OPTICAL TRANSDUCER, METHOD AND LASER DIODE ARRANGEMENT

Title (de)

OPTISCHER SENSOR, VERFAHREN UND LASERDIODENVORRICHTUNG

Title (fr)

TRANSDUCTEUR OPTIQUE, ET PROCEDE ET ENSEMBLE DIODE LASER ASSOCIES

Publication

EP 1012540 A1 (EN)

Application

EP 97919531 A

Priority

  • GB 9701123 W
  • GB 9608370 A
  • GB 9704937 A

Abstract (en)

[origin: WO9740344A1] An optical transducer for determining distance or displacement of a mirror (3) comprises a laser diode (1) which is excited at constant current. The spectrum of the voltage signal across this laser diode is analysed and the spacing between this laser diode and the mirror (3) is determined from the formula f = cm/2L where f is the frequency; c is the speed of light; m is the mode number and L is the effective optical length of the cavity. A force or other transducer can be coupled to the mirror (3) to enable force or other parameters to be determined. In another embodiment the laser beam is conducted to a remote optical cavity of variable length by an optic fibre and the frequencies in the remote cavity are measured by analysing the voltage signal across the laser diode.

IPC 1-7 (main, further and additional classification)

G01D 5/26

IPC 8 full level (invention and additional information)

G01D 5/26 (2006.01)

CPC (invention and additional information)

G01D 5/26 (2013.01)

Citation (search report)

See references of WO 9740344A1

Designated contracting state (EPC)

AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

EPO simple patent family

WO 9740344 A1 19971030; AU 2397097 A 19971112; EP 1012540 A1 20000628

INPADOC legal status

2002-04-17 [18R] REFUSED

- Ref Legal Event Code: 18R

- Effective date: 20011124

2001-07-11 [17Q] FIRST EXAMINATION REPORT

- Ref Legal Event Code: 17Q

- Effective date: 20010528

2000-06-28 [17P] REQUEST FOR EXAMINATION FILED

- Ref Legal Event Code: 17P

- Effective date: 19981119

2000-06-28 [AK] DESIGNATED CONTRACTING STATES:

- Ref Legal Event Code: AK

- Designated State(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE