The present invention provides a projection type
image display device which is corresponding with the requirement of wide angle. The projection type
image display device can reduce the deterioration of imaging capability and the reflection at the surface and is provided with a small-size cover plate. A refractive
optical surface (40b) of the amplifying side of concavo-convex lens (41) at the amplifying side is provided with a convex
surface shape projected to the amplifying side, so the second refractive optical part (40) can function as a protecting cover of projection optical
system (50) when the projection is executed with a wide
visual angle. Thus the thickness of concavo-convex lens (41) is approximately uniform, and furthermore the concavo-convex lens (41) is set to a convex
surface shape projected to the amplifying side, so the surface area as protecting cover can be reduced, and the effect to imaging can be reduced. Additionally, as the concavo-convex lens (41) is formed to a
concentric sphere shaped dome that the curvature center of lens surface is collocated adjacently to the position of
exit pupil of reflective optical part (30), the effect caused by the concavo-convex lens (41) to the imaging effect can be reduced.