Illumination system and projection apparatus

A projection apparatus, comprising:

• an illumination system, comprising:
• at least one laser light source capable of generating a laser beam;
• at least one two-dimensional anisotropic diffusion sheet, located on a transmission path of the laser beam, configured for allowing the laser beam to have an increasing degree of a divergent angle in a first direction greater than an increasing degree of a divergent angle in a second direction, wherein the first direction is substantially parallel to a slow axis of the laser beam;
• and
• a wavelength conversion device located on the transmission path of the laser beam from the two-dimensional anisotropic diffusion sheet, the wavelength conversion device comprising at least one wavelength conversion region and at least one light transmission region, the at least one wavelength conversion region and the at least one light transmission region being adapted to move onto the transmission path of the laser beam by turns, wherein the laser beam passes through the wavelength conversion device when the at least one light transmission region moves onto the transmission path of the laser beam, and the laser beam is converted into at least one converted beam by the at least one wavelength conversion region when the at least one wavelength conversion region moves onto the transmission path of the laser beam, wherein a surface of the two-dimensional anisotropic diffusion sheet has a plurality of ellipsoid-shaped grooves, and a long axis of each of the ellipsoid-shaped grooves is substantially orthogonal to a fast axis of the laser beam;
• a light valve located on the transmission path of the laser beam and a transmission path of the converted beam, and configured to convert the laser beam and the converted beam into an image beam;
• and
• a projection lens located on a transmission path of the image beam.