Head worn computer display systems

Aspects of the present disclosure relate to mounting electronics and optical systems in head-worn see-through computer displays. In embodiments, a head worn computer includes an optical chassis with a rigid open box structure configured to provide a stable optical mounting reference plane and a plurality of image source reference planes. The head worn computer further includes a first image source mounted on one of the image source reference planes to project first image light through a first hole in the optical mounting reference plane and a second image source mounted on a second of the image source reference planes and configured to project second image light through a second hole in the optical mounting reference plane. An outer frame holds the optical chassis such that, when worn by a user, the first and second image light is aligned with the eyes of the user.