Viewing optical system and image display apparatus using the same

A viewing optical system comprising:

• an image forming member for forming a first image to be viewed by an observer;
• an ocular optical system arranged to lead the image formed by said image forming member to an observer's eyeball;
• and
• a see-through optical element placed closer to a second image, which is different from said first image, than said ocular optical system so as to lead said second image to the observer's eyeball,
• wherein said ocular optical system has at least one reflecting surface with a curved surface configuration arranged to reflect a light beam from said first image and to lead it toward the observer's eyeball, said reflecting surface having a transmitting action to allow a light beam from said second image to enter said ocular optical system after passing through said see-through optical element, and
• said see-through optical element is placed closer to said second image than said reflecting surface at a distance from said reflecting surface, and
• wherein when the light beam from said second image passes through said see-through optical element and said ocular optical system, a combined optical power P of said see-through optical element and said ocular optical system is approximately zero, and a combined angular magnification β of said see-through optical element and said ocular optical system is approximately 1.

A viewing optical system comprising:

• an image forming member for forming a first image to be viewed by an observer;
• an ocular optical system arranged to lead the image formed by said image forming member to an observer's eyeball;
• and
• a see-through optical element placed closer to a second image, which is different from said first image, than said ocular optical system so as to lead said second image to the observer's eyeball,
• wherein said ocular optical system has at least one reflecting surface with a curved surface configuration arranged to reflect a light beam from said first image and to lead it toward the observer's eyeball, said reflecting surface having a transmitting action to allow a light beam from said second image to enter said ocular optical system after passing through said see-through optical element;
• and
• said see-through optical element is placed closer to said second image than said reflecting surface in such a manner as to be in close contact with said reflecting surface, and
• wherein when the light beam from said second image passes through said see-through optical element and said ocular optical system, a combined optical power P of said see-through optical element and said ocular optical system is approximately zero.

A viewing optical system comprising:

• an image forming member for forming a first image to be viewed by an observer;
• an ocular optical system arranged to lead the image formed by said image forming member to an observer's eyeball;
• and
• a see-through optical element placed closer to a second image, which is different from said first image, than said ocular optical system so as to lead said second image to the observer's eyeball,
• wherein said ocular optical system has at least one reflecting surface with a curved surface configuration arranged to reflect a light beam from said first image and to lead it toward the observer's eyeball, said reflecting surface having a transmitting action to allow a light beam from said second image to enter said ocular optical system after passing through said see-through optical element, and
• said see-through optical element is placed closer to said second image than said reflecting surface in such a manner as to be in close contact with said reflecting surface, and
• wherein when the light beam from said second image passes through said see-through optical element and said ocular optical system, a combined angular magnification β of said see-through optical element and said ocular optical system is approximately 1.