Virtual image display device including first and second light guiding units and manufacturing method thereof

A virtual image display device comprising:

• a display light guiding unit;
• and
• an image forming unit that emits image light to the display light guiding unit,
• wherein the display light guiding unit includes a first light guiding unit that guides image light corresponding to a first angle of view, and a second light guiding unit that guides image light corresponding to a second angle of view, among angles of view of image light emitted from the image forming unit,
• wherein the first light guiding unit and the second light guiding unit each include an incident side diffraction element that takes the image light inside, and an emission side diffraction element that emits the image light outside,
• wherein the incident side diffraction elements of the first and second light guiding units are offset from one another in a direction in which light can propagate in the first and second light guiding units,
• wherein a pair of the incident side diffraction elements of the first and second light guiding units, or a pair of the emission side diffraction elements of the first and second light guiding units have a common area for diffracting common image light, and
• wherein an addition value of diffraction efficiencies of the pair of diffraction elements in the common area is adjusted so as to be approximately equal to a diffraction efficiency of a single one of the pair of diffraction elements in a non-common area.