SEE-THROUGH COMPUTER DISPLAY SYSTEMS

1 . A compact head-worn display with display optics that have an optical axis that is multiply folded, providing displayed images overlaid onto a see-through view of a surrounding environment comprising:

a. an image source that provides image light associated with the displayed images;

b. an upper optics module including multiple optical elements that provide optical power and a first fold of the optical axis;

c. a lower optics module that including a combiner that provides a second fold of the optical axis to direct the image light towards a user's eye while also allowing light from the surrounding environment to pass through to the user's eye so that the displayed images are seen by the user as overlaid onto a see-through view of a surrounding environment; and

d. wherein, the upper optics include a solid prism that provides optical power and a mirror to fold the optical axis and direct the image light toward the lower optics module.

2 . The compact head-worn display of claim 1 wherein, the image source is a self-luminous microdisplay.

3 . The compact head-worn display of claim 1 wherein, the image source is an OLED microdisplay.

4 . The compact head-worn display of claim 1 wherein, the image source is a backlit LCD microdisplay.

5 . The compact head-worn display of claim 3 wherein, the mirror of the solid element is a partial mirror and a camera for capturing images of the user's eye is positioned behind the partial mirror.

6 . The compact head-worn display of claim 5 wherein, the partial mirror is a cold mirror that reflects visible light and transmits infrared light, and the camera captures infrared images of the user's eye.

7 . The compact head-worn display of claim 2 wherein, the image source is a reflective microdisplay.

8 . The compact head-worn display of claim 2 wherein, the image source is an LCOS or FLCOS

9 . The compact head-worn display of claim 2 wherein, the image source is a DLP.

10 . The compact head-worn display of claim 8 wherein, the mirror of the solid prism is a partial mirror with a backlight positioned behind the partial mirror to provide illuminating light to the image source.

11 . The compact head-worn display of claim 10 wherein, the partial mirror is a reflective polarizer that transmits a portion of the illuminating light and a polarization state of the illuminating light is changed when reflected by the image source to provide image light so that the image light is reflected by the partial mirror.

12 . The compact head-worn display of claim 2 wherein, the material of the solid prism has a different index of refraction than the materials of the other optical elements in the upper optics module.

13 . The compact head-worn display of claim 12 wherein, the materials and optical power associated with the multiple optical elements of the upper optical module are selected to reduce lateral color in the displayed images provided to the user's eye.

14 . The compact head-worn display of claim 13 wherein, the material of the solid prism has a higher refractive index than the materials of the other optical elements in the upper optics module.

15 . The compact head-worn display of claim 14 wherein, the optical power of the solid prism is selected to reduce the overall size of the upper optics module.

16 . The compact head-worn display of claim 2 wherein, the upper optics module further comprises a field lens adjacent to the image source and a power lens adjacent to the lower optics module.

17 . The compact head-worn display of claim 16 wherein, a fold angle associated with the solid prism is selected to reduce the overall size of the upper optics module.

18 . The compact head-worn display of claim 16 wherein, the solid prism is selected to reduce the overall height of the upper optics module.