See-through computer display systems

A head-worn display providing displayed images overlaid onto a see-through view of a surrounding environment comprising:

• a solid prism with a display surface and a planar surface, wherein the planar surface is opposite the display surface and the planar surface is not parallel to the display surface;
• a flat partially reflective plate bonded to the planar surface that transmits a portion of an illuminating light and reflects a portion of an image light associated with the displayed images directly out of the solid prism;
• a reflective image source that reflects the illuminating light to provide the image light;
• and
• a backlight attached to the planar surface including a prism film to direct a portion of the illuminating light toward the reflective image source, wherein the prism film is oriented with the prisms facing away from the reflective image source and toward a light source for the illuminating light.