Abstract: An optical system disposes a total reflection lens between a light valve and a projection lens. When a white light beam, emitting from a light source, passes through a color-generating device, the color of the light beam is sequentially converted into red, green, and blue primaries, and uniformed by an integrator. Then, the light beam impinges into the total reflection lens and is reflected to the light valve. The light valve reflects the light beam into a projection lens to be projected on a screen. Therefore, this invention increases the projection efficiency, and reduces the bulk and components of the optical system.

Abstract: A projection optical system includes a light source emitting light, a light valve with a surface in front of the light source, and a wedge prism disposed in the optical path from the light source to the light valve. By means of the wedge prism with different sectional thickness, the optical path and focus position of the light beam can be corrected. Therefore, the distortion produced by oblique incidence on to the light valve can be improved such that the light optical focus on the surface of the light valve to achieve the improvement of light spot on light valve and raise the uniformity, collection efficiency, and brightness.

Abstract: The optical system of a projection display apparatus comprises a light source, a prism, a light valve, and a projection lens. Wherein a light beam emitting from the light source impinges into the prism, and passes through the first surface of the prism directly to illuminate the light valve which is placed near the first surface and parallels the first surface. By the reflection of the light valve, the light beam impinges into the first surface again, and illuminates a total internal reflection surface with an incidental angle large than the critical total reflection angle, so as to reflect the light beam out of the second surface of the prism and impinge to projection lens to form an image. Therefore, the optical system can increase the transmission and decrease the components, and the volume of it will be more compact.

Abstract: A method for improving a symmetrical projection is provided. The projection system includes a light source, a light valve, and an integration rod. The method utilizes the light source to emit light beams that travel through the integration rod and obliquely project onto the light valve, and adjusting a cross section of the integration rod to offset image distortion existing in the projection system.

Abstract: An system and method for improving asymmetric projection comprising a light source producing a light beam to form a light path, a projection lens disposed in the light path, a light valve inserted in the light path between the light source and the projection lens, and at least one anamorphic surface unit placed in the light path between the light source and the light valve. The anamorphic surface unit offsets a distortion of a light spot resulted from obliquely incidence on the light valve, thus an asymmetriclight spot can be improved as a more symmetric one to increase illuminating collection efficiency and uniformity.