Patent attributes
A projection-type display device includes: a display element including a rectangular displayable region in which an image is displayable; and a projection optical system. Assuming that a focal length of the projection optical system is f and a length of a long side of the displayable region is w, 0.15<|f|/w<0.45 is satisfied. An absorption layer that absorbs light is provided in at least a portion of a non-optically effective surface of a lens which is disposed closer to a reduction side than a first lens closest to an enlargement side in the projection optical system and at least a part of a portion which is irradiated with light that has been emitted from an image and reflected by an enlargement-side surface of the first lens or a reduction-side surface of the first lens.
