(19)
(11) EP 0 563 516 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
22.03.1995 Bulletin 1995/12

(43) Date of publication A2:
06.10.1993 Bulletin 1993/40

(21) Application number: 93100574.8

(22) Date of filing: 15.01.1993
(51) International Patent Classification (IPC)5: G08G 1/04
(84) Designated Contracting States:
DE ES FR GB IT PT

(30) Priority: 17.01.1992 IT BO920020
17.01.1992 IT BO920021
12.06.1992 IT BO920240

(71) Applicant: CONTROL CARD S.r.l.
I-20149 Milano (IT)

(72) Inventor:
  • Ferri, Mario
    I-40033 Casalecchio di Reno (IT)

(74) Representative: Plebani, Rinaldo et al
c/o Studio Torta, Via Viotti 9
10121 Torino
10121 Torino (IT)


(56) References cited: : 
   
       


    (54) Optical barrier for detecting moving objects


    (57) A barrier (1) comprising a transmitting unit (4) set up on one side of a path and having a number of infrared-emitting diodes (5) multiplexed and modulated at a predetermined frequency; a receiving unit (6) set up on the opposite side of the path and having a number of infrared photoreceivers (7); and electronic equipment (8) for controlling the electric signals generated by the photoreceivers (7). The electronic equipment (8) comprises an electronic processing unit (14) for automatically determining a reference value (Vf) for each of the photoreceivers (7); for comparing the signals generated by the photoreceivers (7) with the reference value (Vf); and for checking the comparison and so indicating the status, clear or engaged, of the barrier.






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