Patent ID: 7719769

Claim:
A head mount image display system comprising: a display device; an eyepiece optical system which forms a virtual image of an image displayed on the display device, and which includes a reflection member which shifts an optical axis in the eyepiece optical system to direct the light to a user's eye, wherein the reflection member comprises one of a total reflection mirror and a total reflection prism; an eyepiece window through which the light for forming the virtual image is directed to the user's eye from the reflection member; an eyepiece window holder which holds the eyepiece window within a field of view of the user's eye; and a supporter which is adapted to be fitted onto the user's head and which supports the eyepiece window holder, the eyepiece optical system, and the display device; wherein the eyepiece window has a width of not more than 4 mm that is smaller than a pupil's diameter projected in a visual axis direction of the user's eye, when the supporter is fitted onto the user's head and the eyepiece window is positioned within a field of view of the user's eye; wherein an exit pupil is positioned at least one of: (i) in a vicinity of the eyepiece window, and (ii) between the eyepiece window and a pupil of the user's eye; and wherein the eyepiece window does not completely block substantially parallel light from outside the head mount image display system from entering the pupil of the user's eye.