Light-guiding prism and head-mounted video display apparatus using the same

A light-guiding prism includes a first optical surface which is a surface of incidence on which image light from a display element is incident, and a second optical surface, a third optical surface, a fourth optical surface, and a fifth optical surface which are at least four optical surfaces disposed to surround an optical path of the image light that is incidence from the first optical surface. A sixth optical surface reflects the image light that is guided in a prism surrounded by that at least four side surfaces, which are the second optical surface, the third optical surface, the fourth optical surface, and the fifth optical surface. The fourth optical surface and the fifth optical surface are inclined at a surface perpendicular to a surface include an incident-light axis of the image light, made by the incident-light axis and a reflected-light axis of the sixth optical surface. Moreover, the fourth optical surface and the fifth optical surface are inclined at a surface perpendicular to the incident-light axis. Furthermore, the sixth optical surface which is a reflecting surface has a rectangular shape.