Display apparatus and light guide device

A display apparatus comprising:

• an image generation system;
• and
• a light guide device that includes a transparent light guide portion which guides image light beams emitted from the image generation system to a light-emitting portion, the light guide portion having one end side on which the image light beams are incident and another end side opposing the one end side in a first direction;
• wherein the light guide portion includes a first surface extending from the one end side toward the another end side in the first direction, a second surface extending in the first direction so as to be parallel to the first surface on one side of a second direction intersecting with the first direction, and a plurality of partial reflection surfaces which are disposed along the first direction between the first surface and the second surface and are inclined at the same angle from a normal direction with respect to the second surface toward the one end side,
• wherein intervals between the plurality of partial reflection surfaces in the first direction are widened from the one end side toward the another end side, the plurality of partial reflection surfaces include partial reflection surfaces with which intervals are widened from the one end side toward the another end side in the first direction for each interval, and an amount of widening of the intervals increases from the one end side toward the another end side in the first direction,
• wherein the light guide portion is configured to be mounted on the head of an observer with the first direction extending between the left and right of the head, where the light guide portion is disposed in front of an eye of the observer with the another end side closer to the nose of the observer in the first direction than the one end side is, with the light guide portion being inclined such that the another end side is further away from the face of the observer in the second direction than the one end side is,
• wherein, in two partial reflection surfaces adjacent to each other in the first direction among the plurality of partial reflection surfaces, an angle formed by an imaginary straight line and a portion of the second surface extending toward the one end side is equal to or larger than 90°, the imaginary straight line being a line connecting an end portion of one of the two partial reflection surfaces, which is positioned on the one end side in the first direction, on one side of the second direction and an end portion of the other of the two partial reflection surfaces, which is positioned on the another end side in the first direction, on the another side of the second direction, and
• wherein the angle in each pair of two adjacent partial reflection surfaces increases from the one end side toward the another end side in the first direction.