Abstract: A projection lens includes a first lens group, a second lens group, and a third lens group. The first lens group is composed of a first lens. The first lens has a concave surface and a convex surface, and the concave surface of the first lens faces a reducing side of the projection lens. The second lens group has positive refractive power, and includes a second lens having positive refractive power and a third lens having negative refractive power. The second lens is a biconvex lens, and the third lens has a concave lens facing the reducing side. The third lens group is composed of a fourth lens, and the fourth lens has a convex surface facing a magnifying side of the projection lens. The first lens group, the second lens group, and the third lens group include at least two aspheric lenses.

Abstract: A fixed-focus lens disposed between an object side and an image side is provided. The fixed-focus lens includes a reflector, a curved reflector, a first lens group, and a second lens group disposed in sequence from the object side to the image side. The first lens group includes two aspheric lenses. The second lens group includes a spherical lens and an aspheric lens, wherein the aspheric lens of the second lens group is closest to the image side in the second lens group. Besides, an effective focal length (EFL) of the fixed-focus lens is f, an EFL of the second lens group is f2, and a clear aperture of the aspheric lens of the second lens group is D. The fixed-focus lens satisfies one of following conditions: 0.04<f/f2<0.078 and 0.05<f/D<0.18. An apparatus integrating optical projection and image detection is provided.

Abstract: An image system adapted to a projection display apparatus includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, an aspheric reflector, and a curved reflector. The second lens group includes an aspheric lens which is the nearest to the light valve in the second lens group. A material of the aspheric lens includes glass, the thermal-optical coefficient of the glass is between 1.0×10?6/K and 12.5×10?6/K, and the refractive index of the glass is between 1.482 and 1.847. The aspheric reflector is disposed front of the first lens group for reflecting the image beam passing through the first lens group and second lens group. The curved reflector is disposed above the first lens group for reflecting the image beam reflected by the aspheric reflector onto the screen. The image system has a good imaging quality.

Abstract: A fixed focus lens includes, numbered in order of location from an object side to an image side, a first lens, a second lens, a third lens, and a fourth lens. The first lens is a biconvex lens with a positive refractive power, and the second lens is a convex-concave lens with a negative refractive power. The third lens is a concave-convex lens with a positive refractive power, and the fourth lens is an aspherical lens having a negative refractive power in the centre portion thereof and a positive refractive power at the periphery portion thereof. The fixed focus lens satisfies the condition: 1.0>|(1/r2?1/r1)|>0.6, where r1 denotes the radius of curvature of a front surface of the second lens and r2 denotes the radius of curvature of a rear surface of the first lens.

Abstract: A projection lens includes a first lens group, a second lens group, and a third lens group. The first lens group is composed of a first lens. The first lens has a concave surface and a convex surface, and the concave surface of the first lens faces a reducing side of the projection lens. The second lens group has positive refractive power, and includes a second lens having positive refractive power and a third lens having negative refractive power. The second lens is a biconvex lens, and the third lens has a concave lens facing the reducing side. The third lens group is composed of a fourth lens, and the fourth lens has a convex surface facing a magnifying side of the projection lens. The first lens group, the second lens group, and the third lens group include at least two aspheric lenses.

Abstract: An optical projection system includes an image generation element, a projection lens set for receiving an image from the image generation element, refracting the image and projecting the image out, and a reflector for reflecting the image from the projection lens set and projecting the image to a screen. The projection lens set includes an aspherical lens with a distortion coefficient larger than 0.5 for producing a pincushion distortion of the image and several other lenses, and the absolute value of the sum of the distortion coefficients of the other lenses are less than the distortion coefficient of the aspherical lens. The reflector produces a barrel distortion to the image for compensating a pincushion distortion of the image produced by the projection lens set.

Abstract: A fixed-focus lens disposed between an object side and an image side is provided. The fixed-focus lens includes a reflector, a curved reflector, a first lens group, and a second lens group disposed in sequence from the object side to the image side. The first lens group includes two aspheric lenses. The second lens group includes a spherical lens and an aspheric lens, wherein the aspheric lens of the second lens group is closest to the image side in the second lens group. Besides, an effective focal length (EFL) of the fixed-focus lens is f, an EFL of the second lens group is f2, and a clear aperture of the aspheric lens of the second lens group is D. The fixed-focus lens satisfies one of following conditions: 0.04<f/f2<0.078 and 0.05<f/D<0.18. An apparatus integrating optical projection and image detection is provided.

Abstract: A fixed focus lens includes, numbered in order of location from an object side to an image side, a first lens, a second lens, a third lens, and a fourth lens. The first lens is a biconvex lens with a positive refractive power, and the second lens is a convex-concave lens with a negative refractive power. The third lens is a concave-convex lens with a positive refractive power, and the fourth lens is an aspherical lens having a negative refractive power in the centre portion thereof and a positive refractive power at the periphery portion thereof. The fixed focus lens satisfies the condition: 1.0>|(1/r2?1/r1)|>0.6, where r1 denotes the radius of curvature of a front surface of the second lens and r2 denotes the radius of curvature of a rear surface of the first lens.

Abstract: A fixed-focus lens including a first lens group and a second lens group is provided. The first lens group has a negative refractive power, and consists essentially of a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from an object side to an image side. Refractive powers of the first, second, third, and fourth lenses are negative, negative, positive, and negative respectively. The second lens group is disposed between the first lens group and the image side, and has a positive refractive power. The second lens group includes a fifth lens and a sixth lens arranged in sequence from the object side to the image side. Refractive powers of the fifth lens and the sixth lens are both positive.

Abstract: A zoom lens including a first lens group with a negative refractive power and a second lens group with a positive refractive power is provided. The first lens group includes a first lens, a second lens, and a third lens arranged from an object side to an image side in sequence. The refractive powers of the first, second, and third lenses are negative, negative, and positive sequentially. The second lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged from the object side to the image side in sequence. The refractive powers of the fourth, fifth, sixth, and seventh lenses are positive, positive, negative, and positive sequentially. The first lens group and the second lens group are capable of moving between the object side and the image side.

Abstract: An image system adapted to a projection display apparatus includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, an aspheric reflector, and a curved reflector. The second lens group includes an aspheric lens which is the nearest to the light valve in the second lens group. A material of the aspheric lens includes glass, the thermal-optical coefficient of the glass is between 1.0×10?6/K and 12.5×10?6/K, and the refractive index of the glass is between 1.482 and 1.847. The aspheric reflector is disposed front of the first lens group for reflecting the image beam passing through the first lens group and second lens group. The curved reflector is disposed above the first lens group for reflecting the image beam reflected by the aspheric reflector onto the screen. The image system has a good imaging quality.

Abstract: The optical system comprises a light source, a first optical element, a projecting lens, and an electromagnetic-wave sensor. Light from the light source passes the first optical element and the lens sequentially to reach a screen, and light reflected by the screen passes the lens and reaches the electromagnetic-wave sensor via the first optical element.

Abstract: A display is provided including a light source, a light valve, a projection lens, a first planer reflector, a second planer reflector, a curved reflector and a projection plane. The light source is capable of emitting a light beam. The light valve is disposed on a light path of the light beam to transform the light beam into an image light beam. The projection lens is disposed on a light path of the image light beam. The first planer reflector reflects the image light beam from the projection lens. The second planer reflector reflects the image light beam from the first planer reflector. The curved reflector reflects the image light beam from the second planer reflector. The image light beam from the curved reflector is projected on the projection plane to form a projection image.

Abstract: Data coherence checking apparatus, a redundant array of independent disks (RAID) controller and a storage system having the checking apparatus and a method therefor are proposed. The present invention employs an XOR operation unit and an OR operation unit to check the coherence of data to be checked. The XOR operation unit is used to perform XOR operation on the data to be checked. After the XOR operation unit finishes performing the XOR operation on the data of a processing set, it outputs an XOR operation result to the OR operation unit to perform OR operation so as to obtain a check result.

Abstract: An optical projection system includes an image generation element, a projection lens set for receiving an image from the image generation element, refracting the image and projecting the image out, and a reflector for reflecting the image from the projection lens set and projecting the image to a screen. The projection lens set includes an aspherical lens with a distortion coefficient larger than 0.5 for producing a pincushion distortion of the image and several other lenses, and the absolute value of the sum of the distortion coefficients of the other lenses are less than the distortion coefficient of the aspherical lens. The reflector produces a barrel distortion to the image for compensating a pincushion distortion of the image produced by the projection lens set.

Abstract: A fixed-focus lens including a first lens group and a second lens group is provided. The first lens group has a negative refractive power, and consists essentially of a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from an object side to an image side. Refractive powers of the first, second, third, and fourth lenses are negative, negative, positive, and negative respectively. The second lens group is disposed between the first lens group and the image side, and has a positive refractive power. The second lens group includes a fifth lens and a sixth lens arranged in sequence from the object side to the image side. Refractive powers of the fifth lens and the sixth lens are both positive.

Abstract: A zoom lens including a first lens group with a negative refractive power and a second lens group with a positive refractive power is provided. The first lens group includes a first lens, a second lens, and a third lens arranged from an object side to an image side in sequence. The refractive powers of the first, second, and third lenses are negative, negative, and positive sequentially. The second lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged from the object side to the image side in sequence. The refractive powers of the fourth, fifth, sixth, and seventh lenses are positive, positive, negative, and positive sequentially. The first lens group and the second lens group are capable of moving between the object side and the image side.

Abstract: The optical system comprises a light source, a first optical element, a projecting lens, and an electromagnetic-wave sensor. Light from the light source passes the first optical element and the lens sequentially to reach a screen, and light reflected by the screen passes the lens and reaches the electromagnetic-wave sensor via the first optical element.

Abstract: A light source device including a substrate, a first LED chip, a second LED chip, a third LED chip and a light guide element is provided. The first LED chip is disposed on one side of the substrate. The second LED chip is disposed on the other side of the substrate. The third LED chip is disposed above the substrate. The light guide element has a first light-receiving surface corresponding to the first LED chip, a second light-receiving surface corresponding to the second LED chip, a third light-receiving surface corresponding to the third LED chip, and a light-emitting surface. The light guide element correspondingly receives and mixes the light emitted by the first LED chip, the second LED chip and the third LED chip via the first light-receiving surface, the second light-receiving surface and the third light-receiving surface, and then projects the mixed light via the light-emitting surface.

Abstract: A zoom lens of projector including a first and a second lens groups disposed from the image side in order is provided. The first lens group has a negative effective power ?U1. The second lens group has a positive effective power ?U2. The zoom lens has an equivalent power ?0 and a back focal length BFL, where the BFL*?0?1.0, |?U1|?0>0.6, and ?U2/?0>0.6. The size of the image projected on a screen by the projector is adjusted by adjusting the positions of the first lens group and the second lens group.