Patent attributes
A head-mounted display apparatus according to an aspect of the present disclosure includes an imaging light generating device, a first deflection element including a first deflection section configured to deflect imaging light in a first direction and a second deflection section configured to deflect the imaging light in a second direction, a first diffraction element, and a second diffraction element. When a plane surrounded by the principal ray passing plane, the first principal ray, the second principal ray, and the first deflection section is taken as a first plane, and a plane surrounded by the second deflection section, the first principal ray, the second principal ray, and the first diffraction element is taken as a second plane, the first plane overlaps with at least a part of the second plane when viewed from the third direction and does not overlap with the second plane when viewed from the fourth direction.