Screen device, comprising: - a screen roller; - a screen which can be rolled up onto and rolled down from this screen roller; - a motor for driving the roll-up and roll-down movement of the screen; - a bottom lath which is provided on the side of the screen opposite the side where the screen can be rolled up and rolled down; - one or more lath guides which extend at least partly along the lateral sides of the screen for guiding the movement of the bottom lath when the screen is being rolled up and rolled down; - one or more lath guide elements which are provided at the ends of the bottom lath and which are arranged in the one or more lath guides so as to be displaceable in order to guide the movement of the bottom lath when the screen is being rolled up and down; - a tensioning system to tension the screen in the roll-up and roll-down direction; - at least one blocking element which is provided at an end of the bottom lath; and - at least one blocking profile which extends at least partly along a lateral side of the screen, in which the blocking element and the blocking profile are arranged with respect to one another in such a manner that, at an angular rotation of the bottom lath with respect to a perpendicular position with respect to the blocking profile which remains smaller than a predetermined blocking angle, the blocking element can be moved past the blocking profile when the screen is being rolled up and rolled down and that, when the angular rotation exceeds this blocking angle, the blocking element blocks the bottom lath with respect to the blocking profile, characterized in that the motor comprises a motor protection component which ensures that the screen stops or stops and rolls back up again when the motor protection component detects a sudden change in load on the output shaft of the motor and in that the one or more lath guide elements are designed to be displaceable with respect to the bottom lath in the longitudinal direction of said bottom lath. - a screen roller; - a screen which can be rolled up onto and rolled down from this screen roller; - a motor for driving the roll-up and roll-down movement of the screen; - a bottom lath which is provided on the side of the screen opposite the side where the screen can be rolled up and rolled down; - one or more lath guides which extend at least partly along the lateral sides of the screen for guiding the movement of the bottom lath when the screen is being rolled up and rolled down; - one or more lath guide elements which are provided at the ends of the bottom lath and which are arranged in the one or more lath guides so as to be displaceable in order to guide the movement of the bottom lath when the screen is being rolled up and down; - a tensioning system to tension the screen in the roll-up and roll-down direction; - at least one blocking element which is provided at an end of the bottom lath; and - at least one blocking profile which extends at least partly along a lateral side of the screen, in which the blocking element and the blocking profile are arranged with respect to one another in such a manner that, at an angular rotation of the bottom lath with respect to a perpendicular position with respect to the blocking profile which remains smaller than a predetermined blocking angle, the blocking element can be moved past the blocking profile when the screen is being rolled up and rolled down and that, when the angular rotation exceeds this blocking angle, the blocking element blocks the bottom lath with respect to the blocking profile, characterized in that the motor comprises a motor protection component which ensures that the screen stops or stops and rolls back up again when the motor protection component detects a sudden change in load on the output shaft of the motor and in that the one or more lath guide elements are designed to be displaceable with respect to the bottom lath in the longitudinal direction of said bottom lath.