A roller blind actuation assembly for a roller blind system comprising a roller blind tube, the roller blind actuation assembly comprising: an actuation shaft having an actuation axis; first and second roller blind actuation cables (110, 112) having each a spool-mounting end portion and a free end portion (111, 113); a first roller blind-operating system pivotably mounted to the actuation shaft and comprising: a first driving assembly having a first spool member, the spool-mounting end portion of the first roller blind actuation cable being engaged therewith to rotate the first driving assembly about the actuation axis in a first direction when a pulling force is exerted on the free end portion thereof; and a first unidirectional angular coupler selectively couplable to the roller blind tube upon rotation of the first driving assembly about the actuation axis in the first direction; a second roller blind-operating system pivotably mounted to the actuation shaft and comprising: a second driving assembly having a second spool member, the spool-mounting end portion of the second roller blind actuation cable being engaged therewith to rotate the second driving assembly about the actuation axis in a second direction opposed to the first direction when a pulling force is exerted on the free end portion thereof; and a second unidirectional angular coupler selectively couplable to the roller blind tube upon rotation of the second driving assembly about the actuation axis in the second direction; and a biasing member operatively coupling the first and second driving assemblies, characterized in that the biasing member is extending between the first and second unidirectional angular couplers (550, 650). an actuation shaft having an actuation axis; first and second roller blind actuation cables (110, 112) having each a spool-mounting end portion and a free end portion (111, 113); a first roller blind-operating system pivotably mounted to the actuation shaft and comprising: a first driving assembly having a first spool member, the spool-mounting end portion of the first roller blind actuation cable being engaged therewith to rotate the first driving assembly about the actuation axis in a first direction when a pulling force is exerted on the free end portion thereof; and a first unidirectional angular coupler selectively couplable to the roller blind tube upon rotation of the first driving assembly about the actuation axis in the first direction; a first driving assembly having a first spool member, the spool-mounting end portion of the first roller blind actuation cable being engaged therewith to rotate the first driving assembly about the actuation axis in a first direction when a pulling force is exerted on the free end portion thereof; and a first unidirectional angular coupler selectively couplable to the roller blind tube upon rotation of the first driving assembly about the actuation axis in the first direction; a second roller blind-operating system pivotably mounted to the actuation shaft and comprising: a second driving assembly having a second spool member, the spool-mounting end portion of the second roller blind actuation cable being engaged therewith to rotate the second driving assembly about the actuation axis in a second direction opposed to the first direction when a pulling force is exerted on the free end portion thereof; and a second unidirectional angular coupler selectively couplable to the roller blind tube upon rotation of the second driving assembly about the actuation axis in the second direction; and a biasing member operatively coupling the first and second driving assemblies, a second driving assembly having a second spool member, the spool-mounting end portion of the second roller blind actuation cable being engaged therewith to rotate the second driving assembly about the actuation axis in a second direction opposed to the first direction when a pulling force is exerted on the free end portion thereof; and a second unidirectional angular coupler selectively couplable to the roller blind tube upon rotation of the second driving assembly about the actuation axis in the second direction; and a biasing member operatively coupling the first and second driving assemblies, characterized in that the biasing member is extending between the first and second unidirectional angular couplers (550, 650).