Abstract: A HUD for a helmet having an image projector attached to a body and configured to project images. The HUD has a projection optical combiner configured to produce a transparent display of the images. A holder supports the combiner outside the helmet such that the images are visible to a user of the helmet when the head-up display is in use. A forward facing part of the combiner, such as the entire combiner or its forward facing portion, is user replaceable. A system that has the HUD and a spare user replaceable forward facing part and a system having the HUD and the helmet are additionally disclosed.

Abstract: A mobile electronic device comprises a housing with a first housing part, a second housing part and a third housing part. The first and second housing parts are mounted for a slidable movement relative to one another, whilst the third housing part is mounted for pivotable movement relative to the second housing part. It is suggested that FIG. 4 is published with the abstract.

Abstract: A hinge has two hinge arms for rotatably mounting a lower part of an electronic device of a clamshell design at a first rotational axis and for rotatably mounting an upper part of the electronic device at a second rotational axis. When the angle between the lower and second parts is within a first angular range, the hinge arms are rotated against the lower part in order to change the angle and the hinge leverage point is located substantially below the first rotational axis. When the angle is in a second angular range beyond the first angular range, the hinge arms are rotated against the upper part in order to change the angle and to move the leverage point away from the lower part. As such, the stability of the electronic device when the angle is in the second angular range.