Abstract: A fixed-focus lens including a first lens group, a second lens group and a third lens group which are arranged in sequence from an object side to an image side is provided. The first lens group has a negative refractive power and includes a first lens and a second lens arranged in sequence from the object side to the image side, and both having negative refractive powers. The first lens is an aspheric lens. The second lens group has a positive refractive power and includes a lens with positive refractive power. The third lens group has a positive refractive power and includes at least one first cemented lens. The fixed-focus lens satisfies 1.2<|fG1/f|<4.2 and 2.8<|fL2/f|<8.6, where f, fG1 and fL2 are effective focal lengths of the fixed-focus lens, the first lens group and the second lens respectively.

Abstract: A fixed-focus lens including a first lens group, a second lens group, and a third lens group arranged from an object side to an image side in sequence is provided. The first lens group has a negative refractive power, and includes at least one aspheric lens. The second lens group has a positive refractive power, and includes a lens. The third lens group has a positive refractive power, and includes a triple cemented lens. An effective focal length (EFL) of the fixed-focus lens is f. An EFL of the first lens group is f1. An EFL of the second lens group is f2. An EFL of the third lens group is f3. An axial distance between the first lens group and the second lens group is d. The fixed-focus lens satisfies: 2.5<|f1/f|<4.5, 7.5<f2/f<10, 4.5<f3/f<8.5, and 13<d/f<14.

Abstract: A fixed-focus lens including a first lens group, a second lens group and a third lens group, which are arranged in sequence from an object side to an image side, is provided. The first lens group has a negative refractive power and includes three lenses arranged from the object side to the image side. The lens, closest to the object side, of the first lens group is an aspheric lens. The second lens group has a positive refractive power and includes two lens arranged from the object side to the image side. The third lens group has a positive refractive power and includes six lenses arranged from the object side to the image side. Refractive powers of the lenses of the third lens group in sequence from the object side to the image side are negative, positive, negative, positive, positive and positive.

Abstract: A zoom lens includes a first lens group with a negative refractive power and a second lens group with a positive refractive power, wherein the second lens group is disposed between the first lens group and an image side, and the first lens group and the second lens group are suitable for moving between an object side and the image side. In addition, the first lens group includes a first lens with a negative refractive power, and the first lens is a meniscus lens with a convex surface facing the object side and has an Abbe number greater than 50. A focal length of the zoom lens is F, a focal length of the first lens group is F1, a curvature radius of a surface facing the second lens group of the first lens is R2, and ?0.6<F/F1<?0.2, 0.7<R2/F<1.8.

Abstract: A fixed-focus lens including a first lens group, a second lens group, and a third lens group is provided. The first lens group has a negative refractive power, includes a plurality of lenses, and is disposed between an object side and an image side. The lenses of the first lens group include at least one aspheric lens. The second lens group is disposed between the first lens group and the image side and has a positive refractive power. The third lens group is disposed between the second lens group and the image side and has a positive refractive power. The third lens group includes a first triple cemented lens and a second triple cemented lens arranged from the object side to the image side in sequence.

Abstract: A zoom lens includes a first lens group with a negative refractive power and a second lens group with a positive refractive power. The first lens group includes a first lens, a second lens, a third lens and a fourth lens arranged in sequence and refractive powers thereof are negative, negative, negative and positive respectively. The first and second lenses are meniscus lenses and two surfaces of the second lens are aspheric surfaces. The third lens is a biconcave lens and the fourth lens is a biconvex lens. The second lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in sequence and refractive powers thereof are positive, positive, positive, negative and positive respectively. A cemented doublet lens is composed of the seventh and eighth lenses. The ninth lens is a biconvex lens.

Abstract: A fixed-focus lens includes a first lens group and a second lens group. The two lens groups have positive refractive powers. The first lens group is composed of a first negative lens, a second negative lens, a third negative lens, a fourth positive lens and a fifth positive lens arranged in sequence from an object side to an image side. The first lens is an aspheric lens. The second lens group is composed of two cemented lens and a positive lens between them. The fixed-focus lens satisfies the following conditions: (1)5.0<FL45/F<7.5; (2)3.5<FG2/F<4.8; (3)FG2/H>3.755, wherein FL45 is an effective focal length (EFL) from the fourth lens to the fifth lens, FG2 is an EFL of the second lens group, F is an EFL of the fixed-focus lens, and H is the maximum image height of the image side.

Abstract: A zoom lens includes a first lens group with a negative refractive power and a second lens group with a positive refractive power. The first lens group includes a first lens, a second lens, a third lens and a fourth lens arranged in sequence and refractive powers thereof are negative, negative, negative and positive respectively. The first and second lenses are meniscus lenses and two surfaces of the second lens are aspheric surfaces. The third lens is a biconcave lens and the fourth lens is a biconvex lens. The second lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in sequence and refractive powers thereof are positive, positive, positive, negative and positive respectively. A cemented doublet lens is composed of the seventh and eighth lenses. The ninth lens is a biconvex lens.

Abstract: A zoom lens includes a first lens group with a negative refractive power and a second lens group with a positive refractive power, wherein the second lens group is disposed between the first lens group and an image side, and the first lens group and the second lens group are suitable for moving between an object side and the image side. In addition, the first lens group includes a first lens with a negative refractive power, and the first lens is a meniscus lens with a convex surface facing the object side and has an Abbe number greater than 50. A focal length of the zoom lens is F, a focal length of the first lens group is F1, a curvature radius of a surface facing the second lens group of the first lens is R2, and ?0.6<F/F1<?0.2, 0.7<R2/F<1.8.

Abstract: A projection display system comprises an illumination device, a prism assembly, a projection lens and a reflective light valve. The prism assembly has a first light incident surface, a first light emitting surface and a second light emitting surface. The first light emitting surface is an optical curved surface. An illumination beam is incident on the light valve after it enters the prism assembly from the first light incident surface. A modulated beam is generated after it is processed through the light valve. Finally, the modulated beam is projected into the projection lens through the prism assembly. Because a surface of the prism assembly is set to be an optical curved surface to replace a lens in the projection lens or the illumination device, a back focal length of the system is shortened and the projection lens or the illumination device is simplified.

Abstract: A fixed-focus lens suitable for projecting an image beam from a light valve onto a screen is provided. The fixed-focus lens comprises a first lens group, a second lens group, and a third lens group arranged in sequence. The third lens group is disposed near the light valve. The first lens group having a negative refractive power comprises at least an aspheric lens. The second lens group having a positive refractive power comprises at least a lens. The third lens group having a positive refractive power comprises at least four lenses. A shortest distance between the first and second lens groups is S1-2, the effective focal length of the third lens group is F3, and S1-2/F3>1.51. The effective focal length of the lens closest to the screen in the first lens group is F11. The effective focal length of the fixed-focus lens is F, and F11/F<?l8.5.

Abstract: An illuminating system and method for improving asymmetric projection includes 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 asymmetric light spot can be improved as a more symmetric one to increase illuminating collection efficiency and uniformity.

Abstract: The optical system of a projection display apparatus. The projection display apparatus includes a light source, a prism, a light valve, and a projection lens. A light beam emitted 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 number of components, and reduce its overall volume.

Abstract: A projection display system comprises an illumination device, a prism assembly, a projection lens and a reflective light valve. The prism assembly has a first light incident surface, a first light emitting surface and a second light emitting surface. The first light emitting surface is an optical curved surface. An illumination beam is incident on the light valve after it enters the prism assembly from the first light incident surface. A modulated beam is generated after it is processed through the light valve. Finally, the modulated beam is projected into the projection lens through the prism assembly. Because a surface of the prism assembly is set to be an optical curved surface to replace a lens in the projection lens or the illumination device, a back focal length of the system is shortened and the projection lens or the illumination device is simplified.

Abstract: A projector apparatus includes: a light source, a digital micromirror device for modulating the light beams emitted from the light source into photo signals, an illuminating lens unit for guiding the light beams emitted from the light source towards the digital micromirror device, and an imaging lens unit for guiding and projecting the photo signals generated by the digital micromirror device. into an image. An aperture-controllable diaphragm is disposed in the apparatus, and defines an aperture. The diaphragm includes at least one adjustable blade for altering dimension of the aperture so as to adjust the brightness and contrast of the image.

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: 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: 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: 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.