Image display apparatus and projection optical system

An image display apparatus, comprising:

• a light source;
• an image generation unit for generating image light by modulating light emitted from the light source;
• and
• a projection optical system having
• a lens system configured with reference to a reference axis at a position where the generated image light is incident and having a positive refractive power as a whole, and
• a concave reflection surface configured with reference to the reference axis and reflecting the image light emitted from the lens system toward an object to be projected;
• wherein a relationship
• 0<|Δθ(hmax)−Δθ(0.9·hmax)|/θ(hmax)<0.056
• is satisfied if
• a light beam height from the reference axis is denoted as h,
• an angle with respect to an optical axis height direction of a tangent line of a function Z(h) representing a shape of the concave reflection surface corresponding to the light beam height h is denoted as θ(h),
• an amount of change in the angle θ(h) at the light beam height h is denoted as Δθ(h), and
• the light beam height h of a reflection point farthest from the reference axis of the concave reflection surface for reflecting the image light is denoted as hmax.