Projection apparatus and illumination system

A projection apparatus, comprising:

• an illumination system, comprising:
• a light source, emitting a light beam;
• a first lens element, disposed on a transmission path of the light beam emitted from the light source, wherein the first lens element has a curved surface and a multidirectional-plane, the multidirectional-plane and the curved surface are two opposite surfaces in the first lens element, the multidirectional-plane comprises a plurality of sub-planes formed by being rotated in different directions, the multidirectional-plane has a first midline and a second midline being perpendicular to each other, the first midline and the second midline are respectively perpendicular to an optical axis of the illumination system, and the sub-planes comprise a plurality of first sub-planes and a plurality of second sub-planes, wherein the first sub-planes are respectively formed by rotating a reference plane perpendicular to the optical axis of the illumination system by different angles along the first midline of the multidirectional-plane, and the second sub-planes are respectively formed by rotating the reference plane by different angles along the second midline of the multidirectional-plane, wherein the plurality of formed sub-planes facing different directions refract the light beam from the light source passed through the curved surface to different positions on an optical wavelength conversion module;
• and
• the optical wavelength conversion module, disposed on a transmission path of the light beam transmitted from the first lens element, wherein the optical wavelength conversion module converts a first portion of the light beam transmitted from the first lens element into a converted light beam, and the converted light beam and a second portion of the light beam transmitted from the first lens element form an illumination beam;
• a light valve, disposed on a transmission path of the illumination beam and converting the illumination beam into an image beam;
• and
• a projection lens, disposed on a transmission path of the image beam.