Abstract: A lens system includes a first lens and a second lens formed in turn from an object side to an image side. The lens system satisfies the following conditions: 0.08?D2/D?0.14??(1) 4?h2/z2?12??(2) wherein, D2 is the distance along an optical axis of the lens system from the second surface of the first lens to the third surface of the second lens, D is the distance along an optical axis of the lens system from the first surface of the first lens to fourth surface of the second lens, h2 is the distance from the optical axis of the lens system to the outermost optically effective portion of the second lens surface of the first lens, and z2 is the distance along the optical axis of the lens system from the vertex of the second surface of the first lens to the point of the optical axis where h2 is measured.

Abstract: An exemplary wide-angle lens system includes, in order from the object side to the image side thereof, a first lens element having a negative optical power and crescent-shaped convex to the object side and a second lens element having a positive optical power. The first and second lens elements are plastic, and the wide-angle lens system satisfies the conditions R1F/R1R>1.24, and R2F/R2R>3.28, where R1F is the radius of curvature of an object-side surface of the first lens element, R1R is the radius of curvature of an image-side surface of the first lens element, R2F is the radius of curvature of an object-side surface of the second lens element, and R2R is the radius of curvature of an image-side surface of the second lens element.

Abstract: A projector system includes a light source module and an integrator including a light receiving surface for receiving light from the light source module. The light source module includes a number of light sources for emitting parallel light, multiple sets of light-adjusting prisms corresponding to the light sources and a focusing lens arranged near the integrator. Light emitted from each of the light sources is refracted by the corresponding set of light-adjusting prisms, and then focused by the focusing lens to the light receiving surface of the integrator, and forms into a converging light cone with the apex being at the light receiving surface of the integrator. An angle of the light cone is 1/N of a cone formed by the light without being refracted, where N is number of the light sources and is greater than 1.

Abstract: A lens system includes a first lens and a second lens formed in turn from an object side to an image side. The lens system satisfies the following conditions: 0.08?D2/D?0.14??(1) 4?h2/z2?12??(2) wherein, D2 is the distance along an optical axis of the lens system from the second surface of the first lens to the third surface of the second lens, D is the distance along an optical axis of the lens system from the first surface of the first lens to fourth surface of the second lens, h2 is the distance from the optical axis of the lens system to the outermost optically effective portion of the second lens surface of the first lens, and z2 is the distance along the optical axis of the lens system from the vertex of the second surface of the first lens to the point of the optical axis where h2 is measured.

Abstract: An optical zoom lens includes, in this order from the object side to the image side thereof, a first lens group of negative refraction power, a second lens group of positive refraction power, and a third lens group of positive refraction power. The optical zoom lens satisfies the formulas of: ?0.45 <Fw/f1<?0.3; and 0.4<f2/|f1|<0.8, where Fw is the smallest effective focal length of the optical zoom lens, f1 is the effective focal length of the first lens group, and f2 is the effective focal length of the second lens group.

Abstract: A lens system comprises a first lens negative in power, a second lens positive in power, a third lens negative in power, a fourth lens positive in power, a fifth lens negative in power, and a sixth lens positive in power. The lens system meets a criteria of TT/f?1.68 and 0.3<f/f23<0.4, wherein TT denotes a distance between an object-side surface of the first lens and an image plane of the lens system; f23 denoting an effective focal length of a combination of the second lens and the third lens; f denoting an effective focal length of the entire lens system.

Abstract: A lens system includes a positive refractive power first lens, a negative refractive power second lens, a positive refractive power third lens, and a negative refractive power fourth lens in that order from the object side of the lens system. Wherein the lens system satisfies the following conditions: (1) D1/D2<1.6; and (2) R2/F1>1.8, wherein, D1 is the effective radius of a surface of the third lens facing the image side of the lens system, D2 is a distance from the top point of a surface to the optical center of the third lens, R2 is the radius of curvature of a surface of the first lens facing the image side of the lens system, and F1 is a focal length of the first lens.

Abstract: An illumination system includes an LED and a solid light pipe. The solid light pipe includes an incident surface, an emitting surface opposite to the incident surface, and four reflecting side surfaces joining the incident surface and the emitting surface. An area of the incident surface is smaller than an area of the emitting surface. The LED is positioned in front of the incident surface of the solid light pipe.

Abstract: An exemplary wide-angle lens includes, in this order from the object side to the image side thereof, a first lens having negative refraction of power, a second lens having positive refraction of power, a third lens 30 having positive refraction of power, and a fourth lens having negative refraction of power, wherein the wide-angle lens satisfies the formulas: R1>R2>0, R1/R2>4.5, R8<R7<0, and 2<|R8/R7|<2.25, where R1 is the radius of curvature of the object-side surface of the first lens, R2 is the radius of curvature of the image-side surface of the first lens, R7 is the radius of curvature of the object-side surface of the fourth lens, and R8 is the radius of curvature of the image-side surface of the fourth lens.

Abstract: An exemplary wide-angle lens includes, in this order from the object side to the image side thereof, a first lens having negative refraction of power, a second lens having positive refraction of power, a third lens 30 having positive refraction of power, and a fourth lens having negative refraction of power, wherein the wide-angle lens satisfies the formulas: R1>R2>0, R1/R2>4.5, R8<R7<0, and 2<|R8/R7|<2.25, where R1 is the radius of curvature of the object-side surface of the first lens, R2 is the radius of curvature of the image-side surface of the first lens, R7 is the radius of curvature of the object-side surface of the fourth lens, and R8 is the radius of curvature of the image-side surface of the fourth lens.

Abstract: An optical zoom lens includes, in this order from the object side to the image side thereof, a first lens group of negative refraction power, a second lens group of positive refraction power, and a third lens group of positive refraction power. The optical zoom lens satisfies the formulas of: ?0.45<Fw/f1<?0.3; and 0.4<f2/|f1|<0.8, where Fw is the smallest effective focal length of the optical zoom lens, f1 is the effective focal length of the first lens group, and f2 is the effective focal length of the second lens group.

Abstract: A projecting lens system includes a first lens positive in power, a second lens negative in power, a third lens positive in power, and a fourth lens positive in power. The projecting lens system meets a criteria of 1.4<TT/f<1.7; where TT denotes a total length of the projecting lens system and f denotes an effective focal length of the projecting lens system.

Abstract: A lens system comprises a first lens negative in power, a second lens positive in power, a third lens negative in power, a fourth lens positive in power, a fifth lens negative in power, and a sixth lens positive in power. The lens system meets a criteria of TT/f?1.68 and 0.3<f/f23<0.4, wherein TT denotes a distance between an object-side surface of the first lens and an image plane of the lens system; f23 denoting an effective focal length of a combination of the second lens and the third lens; f denoting an effective focal length of the entire lens system.

Abstract: Digital content processing methods and systems are provided. First, an image property and a specific value corresponding to the image property are determined according to an image enhancement operation. Then, a specific region is sought within a first digital content, wherein pixels in the specific region have the specific value corresponding to the image property. Specific information is embedded in the specific region of the first digital content to generate a second digital content having the specific information. A digital content playback device performs the image enhancement operation on the second digital content to obtain the specific information.

Abstract: An exemplary imaging lens includes, in this order from the object side to the image side thereof, a first lens of positive refraction power, a second lens of negative refraction power, a third lens of positive refraction power, and a fourth lens of negative refraction power. The imaging lens satisfies the formulas of: (1) 0.5<F1/F<1; (2) R6>R5>R7, where F1 is the focal length of the first lens, F is the effective focal length of the imaging lens, R5 is the radius of curvature of the object-side surface of the third lens, R6 is the radius of curvature of the image-side surface of the third lens, and R7 is the radius of curvature of the object-side surface of the fourth lens.

Abstract: A wide-angle image pick-up lens system includes a first lens group with negative refracting power and a second lens group with positive refracting power. The first lens group and the second lens group are aligned in order from an object side to an image side. The first lens group and the second lens group satisfy the following conditions: ?0.15<f10/f12<?0.05, 0.3<f10/f14<0.8, wherein f10 is a focal length system, f12 is an effective focal length of the first lens group, and f14 is an effective focal length of the second lens group. The first lens group includes a third lens with positive refracting power. A refractive index of the third lens is above of 1.85.

Abstract: A novel steganographic approach analogous to the real-world secret communication mechanism, in which messages to be concealed are written on white papers using invisible ink like lemon juice or milk and are revealed only after the papers are heated, is proposed. Carefully designed informed-embedders now play the role of “invisible ink”; some pre-negotiated attacks that can be provided by common content processing tools correspond to required “heating” process. Theoretic models and feasible implementations of the proposed digital-invisible-ink (DII) watermarking approach are provided. The proposed DII watermarking schemes can prevent the supervisor from interpreting secret messages even the watermark extractor, decryption tool, as well as session keys are available to the supervisor.

Abstract: A lens system includes a positive refractive power first lens, a negative refractive power third lens, and a negative refractive power second lens in that order from the object side of the lens system. Wherein the lens system satisfies the following conditions: (1) D/TTL>1.2; (2) 4.5>R1R/R1F>2.2; and (3) f/R1F>3, wherein, D is the diameter of a maximal image circle of the lens system on a image plane of the lens system, TTL is a distance from a surface of the first lens facing the object side of the lens system to the image plane, R1R is the radius of curvature of a surface of the first lens facing the image side of the lens system, R1F is the radius of curvature of the surface of the first lens facing the object side of the lens system, and f is a focal length of the lens system.

Abstract: A lens system comprises a first lens positive in power, a second lens positive in power, a third lens negative in power, a fourth lens positive in power, and a fifth lens negative in power. The lens system meets a criteria of 1.6<TT/f<1.8, 1.6<f/f2<1.8, and ?0.6<f/f5<?0.4, wherein TT denotes a distance between an object-side surface of the first lens and an image plane of the lens system; f2 denoting an effective focal length of the second lens; f denoting an effective focal length of the entire lens system.

Abstract: An exemplary zoom lens for use in projection technology includes, in this order from the magnification side to the minification side thereof, a first lens group having negative refraction of power, a second lens group having positive refraction of power, a third lens group having positive refraction of power, a fourth lens group having negative refraction of power, and a fifth lens group having positive refraction of power, wherein the zoom lens satisfies the formulas: ?1.5<F1/Fw<?1.3, 1.5<F2/Fw<1.8, 1.8<F3/Fw<2.2, ?10<F4/Fw<?5, and 2.3<F5/Fw<2.8, where F1, F2, F3, F4, F5, and Fw respectively represent the effective focal length of the first lens groups, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the shortest effective focal length of the zoom lens.