Patent ID: 8575582

Claim:
A method for the optical monitoring of a monitored zone ( 10 ), wherein light is transmitted by a transmission device ( 30 ) along a transmission light system axis ( 32 ) into the monitored zone ( 10 ); light ( 36 ) reflected back/remitted back from the monitored zone ( 10 ) is detected by a first light receiver ( 44 ) via a first reception light path, with the first light receiver ( 44 ) including at least two spatial detection zones ( 46 , 48 ) which are arranged so that a first detection zone ( 46 ) receives light ( 36 ) reflected back/remitted back when a diffusely reflective object ( 20 ) is located in a scanned zone ( 12 ) of the monitored zone ( 10 ) and a second detection zone ( 48 ) receives light reflected back/remitted back when a diffusely reflective object is located in a background zone ( 14 ) of the monitored zone ( 10 ); and light ( 38 ) reflected back/remitted back from the monitored zone ( 10 ) is detected by a second light receiver ( 50 ) via a second reception light path, with the second light receiver ( 50 ) including at least two spatial detection zones ( 52 , 54 ) which are arranged so that a first detection zone ( 52 ) receives light ( 38 ) reflected back/remitted back when a diffusely reflective object ( 20 ) is located in s scanned zone ( 12 ) of the monitored zone ( 10 ) and a second detection zone ( 54 ) receives light reflected back/remitted back when a diffusely reflected object is located in a background zone ( 14 ) of the monitored zone ( 10 ); wherein the reception light paths are located on different sides of the transmission light system axis ( 32 ), wherein a first output signal ( 60 ) of the first light receiver ( 44 ) is produced in dependence on whether the center of the light ( 36 ) reflected back/remitted back in the direction of the first light receiver ( 44 ) is located in the first detection zone ( 46 ) or in the second detection zone ( 48 ) of the light receiver ( 44 ), with the first output signal ( 60 ) only being able to adopt one of two possible states; a second output signal ( 62 ) of the second light receiver ( 50 ) is produced in dependence on whether the center of the light ( 38 ) reflected back/remitted back in the direction of the second light receiver ( 50 ) is located in the first detection zone ( 52 ) or in the second detection zone ( 54 ) of the light receiver ( 50 ), with the second output signal ( 62 ) only being able to adopt one of two possible states; and the first and the second output signals ( 60 , 62 ) are logically linked with one another to produce an object determination signal ( 66 ).