Abstract: A wide-angle camera for a head-mounted device, includes, but is not limited to, a casing, a biconvex plus lens, and a biconcave minus lens. The biconvex plus lens and the biconcave minus lens are arranged in parallel in the casing and the biconcave minus lens is closer to an object space. The bioconcave minus lens is able to move along an axis of the casing to adjust a distance to the bioconvex plus lens. The focal power of a zooming system of the wide-angle camera is set to be a range from ?0.005 to 0.005, an thus the bioconvex plus lens is stationary in the camera, and a movement of the bioconcave minus lens enables the camera to be suitable for the crowds of 500 degree nearsightedness to 500 degree farsightedness.

Abstract: There is provided an imaging lens with high resolution which satisfies in well balance low-profileness, wide field of view and low F-number. An imaging lens comprises in order from an object side to an image side, a first lens being double-sided aspheric lens, a second lens having positive or negative refractive power, an aperture stop, a third lens having positive refractive power, a fourth lens having at least one aspheric surface and negative refractive power, a fifth lens having at least one aspheric surface and positive or negative refractive power, and a sixth lens being double-sided aspheric lens and having positive refractive power, wherein an image-side surface of said sixth lens is a concave surface facing the image side near the optical axis and is formed as the aspheric surface, which changes from the concave surface to the convex surface at an area apart from the optical axis.

Abstract: An imaging lens includes a first lens group and a second lens group, arranged in this order from an object side to an image plane side. The first lens group includes a first lens, a second lens, and a third lens. The second lens group includes a front side lens group and a rear side lens group. The front side lens group includes a fourth lens and a fifth lens. The rear side lens group includes a sixth lens having two aspheric surfaces and a seventh lens having two aspheric surfaces. The imaging lens has a total of seven single lenses. The first to seventh lenses are arranged respectively with a space in between. The third and fourth lenses have convex surfaces on the image plane side. The fifth lens has a convex surface on the object side. The rear side lens group has a specific focal length.

Abstract: An optical photographing assembly includes, in order from an object side to an image side along an optical axis, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element has positive refractive power. The third lens element has at least one of an object-side surface and an image-side surface being aspheric. The fourth lens element has at least one of an object-side surface and an image-side surface being aspheric. The fifth lens element has at least one of an object-side surface and an image-side surface being aspheric, wherein at least one of the object-side surface and the image-side surface of the fifth lens element includes at least one inflection point.

Abstract: A compact low-profile low-cost imaging lens with a small F-value which offers a wide field of view and corrects aberrations properly. Its elements are spaced from each other and arranged from an object side to an image side as follows: a first positive lens having a convex object-side surface; a second negative lens; a third positive or negative lens; a fourth positive or negative lens; a fifth positive or negative lens; a sixth positive or negative lens; and a seventh lens as a double-sided aspheric lens having a concave image-side surface. The third to sixth lenses each have at least one aspheric surface. The aspheric image-side surface of the seventh lens has a pole-change point off an optical axis. The imaging lens satisfies a conditional expression ?1.0<f1/f2<?0.15, where f1 denotes focal length of the first lens, and f2 denotes focal length of the second lens.

Abstract: A compact low-profile low-cost imaging lens with a small F-value which offers a wide field of view and corrects aberrations properly. Its elements are spaced from each other and arranged from an object side to an image side as follows: a first positive lens having a convex object-side surface; a second negative lens; a third positive or negative lens; a fourth positive or negative lens; a fifth positive or negative lens; a sixth positive or negative lens; and a seventh lens as a double-sided aspheric lens having a concave image-side surface. The third to sixth lenses each have at least one aspheric surface. The aspheric image-side surface of the seventh lens has a pole-change point off an optical axis. The imaging lens satisfies a conditional expression ?1.0<f1/f2<?0.15, where f1 denotes focal length of the first lens, and f2 denotes focal length of the second lens.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens, arranged in this order from an object side to an image plane side. The imaging lens has a total of seven lenses. The first to seventh lenses are arranged respectively with a space in between. The second lens is formed in a meniscus shape near an optical axis. The third lens is formed in a meniscus shape so that a surface on the object side is convex near an optical axis. The sixth lens is formed in a meniscus shape near an optical axis. The seventh lens is formed in a shape so that a surface on the image plane side has at least one inflexion point. The first lens and the second lens have specific Abbe's numbers.

Abstract: An optical system of the present invention includes a plurality of lenses inclusive of an aspheric lens having an aspheric surface. A light absorption portion having thickness distribution in a direction perpendicular to an optical axis of the optical system is provided on the optical axis. Here, a refractive index of the aspheric lens, a refractive index of the light absorption portion, an aspheric sag amount of the aspheric lens, an aspheric sag amount of the light absorption portion, a height of a position in the aspheric lens through which a marginal ray of an axial ray passes, and a height of a position in the light absorption portion through which the marginal ray of the axial ray passes are each appropriately set.

Abstract: An optical assembly for a point action camera or other compact digital camera having a wide field of view, includes multiple lens elements, including at least one lens element that has an aspheric lens surface. The optical assembly is configured to provide a field of view in excess of 120 degrees. The optical assembly includes a ratio of a diameter of a first lens element at the object end of the optical assembly to an image diagonal is less than approximately 3.

Abstract: An imaging lens which uses a larger number of constituent lenses for higher performance and features compactness and a wide field of view. The imaging lens is composed of seven lenses to form an image of an object on a solid-state image sensor. The constituent lenses are arranged in the following order from an object side to an image side: a first lens with positive refractive power; a second lens with positive or negative refractive power; a third lens with negative refractive power; a fourth lens with positive or negative refractive power as a double-sided aspheric lens; a meniscus fifth lens having a convex surface on the image side; a sixth lens with positive or negative refractive power as a double-sided aspheric lens; and a seventh lens with negative refractive power, in which an air gap is provided between lenses.

Abstract: An optical imaging lens may include eight lens elements positioned in an order from an object side to an image side. Through designing concave and/or convex surfaces of the eight lens elements, the optical imaging lens may provide improved imaging quality and optical characteristics while the total length of the optical imaging lens may be shortened.

Abstract: An optical photographing lens assembly includes seven lens elements, which are, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The third lens element has positive refractive power. The seventh lens element has an image-side surface being concave in a paraxial region thereof and including at least one convex shape in an off-axis region thereof. An object-side surface and the image-side surface of the seventh lens element are aspheric.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens, arranged in this order from an object side to an image plane side. The imaging lens has a total of seven lenses. The first to seventh lenses are arranged respectively with a space in between. The first lens is formed in a shape so that a surface thereof on the object side is convex near an optical axis. The fifth lens is formed in a shape so that a surface thereof on the image plane side is concave near an optical axis. The seventh lens is formed in a shape so that a surface thereof on the image plane side has at least one inflexion point and is concave near an optical axis.

Abstract: An optical lens, in order from an object side to an image-forming side, includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The object-side surface of the first lens has an effective diameter ?1. The image-side surface of the first lens has a curvature radius R2 and an effective radius D2. The object-side surface of the second lens has an effective diameter ?2. The optical lens satisfies at least one of the following conditions: 0.2??2/?1, ?2/?1?0.65, 0.65?D2/R2 and D2/R2?1.2.

Abstract: A lens module includes first to seventh lenses each having refractive power and sequentially disposed in numerical order from the first lens to the seventh lens starting from an object side of the lens module, wherein each of the first and second lenses has a meniscus shape and an image-side surface that is convex, and the seventh lens has one or more inflection points on an image-side surface thereof.

Abstract: A photographing lens assembly includes seven lens elements, which are, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The third lens element has positive refractive power. The seventh lens element has an image-side surface being concave in a paraxial region thereof, and at least one of an object-side surface and the image-side surface of the seventh lens element includes at least one inflection point. At least one surface of the seven lens elements is aspheric.

Abstract: A compact low-profile low-cost imaging lens with a small F-value which offers a wide field of view and corrects aberrations properly. Its elements are spaced from each other and arranged from an object side to an image side as follows: a first positive lens having a convex object-side surface; a second negative lens; a third positive or negative lens; a fourth positive or negative lens; a fifth positive or negative lens; a sixth positive or negative lens; and a seventh lens as a double-sided aspheric lens having a concave image-side surface. The third to sixth lenses each have at least one aspheric surface. The aspheric image-side surface of the seventh lens has a pole-change point off an optical axis. The imaging lens satisfies a conditional expression ?1.0<f1/f2<?0.15, where f1 denotes focal length of the first lens, and f2 denotes focal length of the second lens.

Abstract: An optical image capturing lens assembly includes seven lens elements, which are, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The second lens element has negative refractive power. The sixth lens element has an object-side surface and an image-side surface being both aspheric. At least one of object-side surfaces and image-side surfaces of the fifth lens element and the sixth lens element includes at least one critical point in an off-axial region thereof.

Abstract: Techniques are disclosed for particulate matter (PM) measurement in a medium (such as air) using flat-top intensity laser sheet beam generation. The techniques for generating the laser sheet beam may include nonspecialized optical elements (e.g., aspherical, spherical, biconvex, and/or cylindrical lenses) that are cost-effective, reduce the overall footprint of the system, and also provide for relatively increased power efficiencies compared to conventional techniques. The PM measurement system may use the laser sheet beam generated in combination with a medium flow channel to pass the medium through the laser sheet beam, thereby causing particulates within the medium to scatter light, which can be detected using a light sensor (e.g., a photodetector). The scattered light signals can then be analyzed to match them with corresponding particulate sizes and the amount of signals per particulate size can also be determined to measure the size and count of particulates within the medium.

Abstract: An imaging optical lens assembly includes seven lens elements, the seventh lens elements being, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, and a seventh lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. The seventh lens element has an image-side surface being concave in a paraxial region thereof and having a critical point in an off-axis region thereof. The image-side surface and an object-side surface of the seventh lens element are both aspheric.

Abstract: A compact low-profile low-cost imaging lens with a small F-value which offers a wide field of view and corrects aberrations properly. Its elements are spaced from each other and arranged from an object side to an image side as follows: a first positive lens having a convex object-side surface; a second negative lens; a third positive or negative lens; a fourth positive or negative lens; a fifth positive or negative lens; a sixth positive or negative lens; and a seventh lens as a double-sided aspheric lens having a concave image-side surface. The third to sixth lenses each have at least one aspheric surface. The aspheric image-side surface of the seventh lens has a pole-change point off an optical axis. The imaging lens satisfies a conditional expression ?1.0<f1/f2<?0.15, where f1 denotes focal length of the first lens, and f2 denotes focal length of the second lens.

Abstract: A photographing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element with refractive power. The first lens element with positive refractive power has an object-side surface being convex in paraxial region. The second lens element with refractive power has an image-side surface being concave in paraxial region. The third, fourth and fifth lens elements all have refractive powers. The sixth lens element with refractive power has an image-side surface being concave in paraxial region, wherein the image-side surface has at least one convex shape in off-axis region, and both of two surfaces are aspheric. The seventh lens element with refractive power has an object-side surface being concave in paraxial region, and both of two surfaces are aspheric.

Abstract: An imaging lens assembly, including, in order from an object side to an image side: a first lens element having negative refractive power; a second lens element with positive refractive power having an image-side surface being convex; a third lens element, a fourth lens element with positive refractive power having an object-side surface being concave and an image-side surface being convex; a fifth lens element with negative refractive power having an image-side surface being concave, at least one convex shape on the image-side surface in an off-axial region, and both of object-side and image-side surfaces thereof being aspheric; wherein the imaging lens assembly has a total of five lens elements.

Abstract: There is provided an optical imaging system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens includes a negative refractive power and a concave object-side surface. The second lens includes a concave object-side surface. The fourth lens includes a negative refractive power. The sixth lens includes an inflection point formed on an image-side surface thereof. The first to sixth lenses are sequentially disposed from an object side toward an imaging plane.

Abstract: An imaging lens includes a first lens group and a second lens group, arranged from an object side to an image plane side. The first lens group includes a first lens, a second lens, and a third lens. The second lens group includes a front side lens group and a rear side lens group. The front side lens group includes a fourth lens and a fifth lens. The rear side lens group includes a sixth lens and a seventh lens both having two aspheric surfaces. The imaging lens has a total of seven single lenses. The first to seventh lenses are arranged respectively with a space in between. The third lens has convex surfaces on both sides. The fourth lens has a concave surface on the object side. The fifth lens has a concave surface on the image plane side. The rear side lens group has a specific focal length.

Abstract: The invention provides a camera lens. The camera lens includes, in an order from an object side to an image side: a first lens with a negative refractive power, a second lens with a positive refractive power, a third lens with a positive refractive power, a fourth lens with a negative refractive power, a fifth lens with a positive refractive power, and a sixth lens with a negative refractive power. Further, the camera lens satisfies specific conditions for improving better performance.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens, arranged in this order from an object side to an image plane side. The imaging lens has a total of seven lenses. The first to seventh lenses are arranged respectively with a space in between. The first lens is formed in a shape so that a surface on the object side is convex near an optical axis. The second lens is formed in a shape so that a surface on the image plane side is concave near an optical axis. The fifth lens is formed in a shape so that a surface on the image plane side is concave near an optical axis. The seventh lens is formed in a shape so that a surface on the image plane side has one inflexion point.

Abstract: The present disclosure discloses a camera optical lens, including, in an order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens is made of plastic material, the second lens is made of plastic material, the third lens is made of glass material, the fourth lens is made of plastic material, the fifth lens is made of plastic material, and the sixth lens is made of glass material. The camera optical lens further satisfies specific conditions.

Abstract: An imaging lens includes a first lens having at least one aspheric surface and positive refractive power; a second lens having at least one aspheric surface and negative refractive power; a third lens having at least one aspheric surface; a fourth lens having at least one aspheric surface; a fifth lens having at least one aspheric surface; a sixth lens having two aspheric surfaces; and a seventh lens having two aspheric surfaces, arranged in this order from an object side to an image plane side respectively with a space in between. The imaging lens has a total of seven lenses. The fifth lens is disposed away from the sixth lens by a specific distance on an optical axis.

Abstract: The present disclosure discloses a camera optical lens. The camera optical lens including, in an order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens is made of plastic material, the second lens is made of plastic material, the third lens is made of plastic material, the fourth lens is made of glass material, the fifth lens is made of glass material, and the sixth lens is made of plastic material. The camera optical lens further satisfies specific conditions.

Abstract: A photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first lens element with refractive power has an object-side surface being convex in a paraxial region thereof. Each second, third, fourth and fifth lens element has refractive power. The sixth lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, and both of the surfaces of the sixth lens element are aspheric. The seventh lens element with refractive power has an image-side surface being concave in a paraxial region thereof, wherein the image-side surface has at least one convex shape in an off-axis region thereof.

Abstract: An optical-lens-set includes a first lens element of a concave image-side surface near its optical-axis, a sixth lens element of negative refractive power and of a concave image-side surface near its optical-axis to go with a fifth lens element of a concave object-side surface near its optical-axis or with a seventh lens element of negative refractive power. The Abbe number ?1 of the first lens element, the Abbe number ?3 of the third lens element, the Abbe number ?4 of the fourth lens element, the Abbe number ?5 of the fifth lens element, the Abbe number ?6 of the sixth lens element and the Abbe number ?7 of the seventh lens element together satisfy 5?5?1?(?3+?4+?5+?6+?7).

Abstract: The present disclosure discloses a camera optical lens. The camera optical lens including, in an order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The first lens is made of plastic material, the second lens is made of plastic material, the third lens is made of plastic material, the fourth lens is made of glass material, the fifth lens is made of plastic material, the sixth lens is made of glass material, and the seventh lens is made of plastic material. The camera optical lens further satisfies specific conditions.

Abstract: The imaging lens consists of, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power, and is configured such that, during focusing, the first lens group and the third lens group remain stationary with respect to an image plane, the second lens group moves in the direction of an optical axis, the first lens group includes a first-a negative lens and a first-b negative lens successively in order from a position closest to the object side, and that the second lens group includes an aperture stop that moves integrally with the second lens group during focusing.

Abstract: The present disclosure provides for various embodiments of optical imaging lenses. An optical imaging lens may comprise at least eight lens elements positioned in an order from an object side to an image side. By controlling the convex or concave shape of the surfaces of the lens elements and designing parameters satisfying at least an inequality, the optical imaging lens may exhibit improved optical characteristics, the total length of the optical imaging lens may be shortened, and the view angle and f-number may also be improved.

Abstract: An ellipsoid wide angle backlight lens includes a lens body, the lens body being provided with a light exit top face, a light exit side face and a light reflection bottom face, the light exit side face being connected to the light exit top face and the light reflection bottom face, a light source mounting hole being arranged on a center of the light reflection bottom face, an inner wall of the light mounting hole being a light incident face, which being connected to the light reflection bottom face; wherein a light incident convex point is arranged at a top center of the light mounting hole, and surfaces of the light exit top face, the light incident face and the light incident convex point are all in an ellipsoid structure. The ellipsoid structure may reduce the number of used LED lamps and power consumption of a liquid crystal television.

Abstract: A photographing optical lens assembly includes five lens elements with refractive power, in order from an object side to an image side. The first lens element with refractive power has a convex object-side surface. The second lens element with positive refractive power has an object-side surface and an image-side surface both being aspheric. The third lens element has positive refractive power. The fourth lens element with refractive power has a concave object-side surface. The fifth lens element with refractive power has an object-side surface and a concave image-side surface with at least one inflection point, both the object-side surface and the image-side surface being aspheric.

Abstract: A wide angle imaging lens assembly includes a first lens element, an aperture, a second lens element, a third lens element, a fourth lens element, and a fifth lens element from an object side to an image side in order along an optical axis. The first lens element to the fifth lens element each includes an object-side surface facing the object side and an image-side surface facing the image side. The wide angle imaging lens assembly satisfies 1.25?f/f2?2.1 and (R5+R6)/(R5?R6)>0.25, where f is the effective focal length of the wide angle imaging lens assembly, f2 is the focal length of the second lens element, R5 is the radius of curvature of the object-side surface of the third lens element, and R6 is the radius of curvature of the image-side surface of the third lens element.

Abstract: An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. At least one lens among the first to the sixth lenses has positive refractive force. The seventh lens can have negative refractive force, and both surfaces thereof are aspheric. At least a surface of the seventh lens has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the seventh lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens, arranged in this order from an object side to an image plane side. The sixth lens is formed in a shape so that a surface thereof on the image plane side and a surface thereof on the object side have positive curvature radii near an optical axis thereof. The seventh lens is formed in a shape so that a surface thereof on the image plane side has a positive curvature radius near an optical axis thereof. The seventh lens is formed in the shape so that the surface thereof on the image plane side is aspheric. The fourth lens has a specific focal length.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens having negative refractive power, arranged in this order from an object side to an image plane side. The seventh lens is formed in a meniscus shape near an optical axis thereof. The fourth lens has a specific focal length.

Abstract: Compact narrow angle lens systems that may be used in small form factor cameras. The lens system may include six lens elements with refractive power, and may provide lower F-numbers while maintaining or improving imaging quality and package size when compared to other compact lens systems. Total track length of the lens system may be 6.5 millimeters or less, for example 5.9 or 6 millimeters. Focal length of the lens system may be 7.0 millimeters or less, for example 6.6 millimeters. The lens system may include an aperture stop located behind the front vertex of the lens system, for example between the first and second lens elements, that effectively moves the ideal principal point of the camera to in front of the front vertex. The lens system may provide a focal ratio of 2.8 or less, for example 2.6 or 2.4.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens, arranged in this order from an object side to an image plane side. The imaging lens has a total of seven lenses. The first to seventh lenses are arranged respectively with a space in between. The first lens is formed in a shape so that a surface on the object side is convex near an optical axis. The third lens is formed in a shape so that a surface on the object side is convex near an optical axis. The seventh lens is formed in a shape so that a surface on the image plane side has at least one inflexion point and is concave near an optical axis. The fourth lens and the fifth lens have specific Abbe's numbers.

Abstract: An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens; and a seventh lens, arranged from an object side to an image plane side. The imaging lens has a total of seven lenses. The first to seventh lenses are arranged respectively with a space in between. The first lens is formed in a shape so that a surface on the object side is convex near an optical axis. The third lens has a meniscus shape near an optical axis. The fourth lens is formed in a shape so that a surface on the image plane side is convex near an optical axis. The seventh lens is formed in a shape so that a surface on the image plane side has one inflexion point and is concave near an optical axis. The fourth lens has a specific Abbe's number.

Abstract: Provided is a soft focus optical system configured to be arranged on an image side of an image pickup optical system, the soft focus optical system consisting of a negative lens and a positive lens, in which a conditional expression 0.950<B<1.050 is satisfied, where B is a magnification of the soft focus optical system, and in which a conditional expression, |(2Y)2/(fn×fp)|?0.005 is satisfied or conditional expressions, 0.005<|(2Y)2/(fn×fp)|; and fn/fp<?0.750 are satisfied, where fn is a focal length of the negative lens, fp is a focal length of the positive lens, and Y is a maximum image height of the image pickup lens.

Abstract: An imaging lens system includes, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The second lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof. The third lens element with positive refractive power has an image-side surface being convex in a paraxial region thereof. The fourth lens element has positive refractive power. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The sixth lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof.

Abstract: A photographing lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. The third lens element has positive refractive power, wherein both surfaces thereof are aspheric. The fourth lens element has refractive power, wherein both surfaces thereof are aspheric. The fifth lens element has negative refractive power, wherein both surfaces thereof are aspheric. The sixth lens element with positive refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein both of the two surfaces are aspheric.

Abstract: Prism assemblies for projector display systems disclosed receive inputs from discrete color channels (e.g., red, green and blue channels. In one embodiment, “off state” light from the red, green, and blue DLP modulation may be reflected away from on-state light paths within the prism, tending to avoid uncontrolled scatter. In other embodiments, by keeping the colors separate for much of the prism path length, power levels may be significantly reduced at typical failure points. Light efficiency may be increased significantly when using discrete light sources like LEDs and lasers by removal of the additional red, green, and blue separation and re-combination losses.

Abstract: An optical imaging system includes lenses sequentially disposed from an object side toward an imaging plane and including a refractive power in paraxial regions or edges of the paraxial regions. An object-side surface of a fifth lens of the lenses is planar in a paraxial region and the fifth lens includes a refractive power at an edge of the paraxial region.

Abstract: An imaging lens is formed from a first group lens having negative power, a second group lens having positive power, a third group lens having negative power, and a fourth group lens having positive power, disposed in order from the subject side to the image side. Letting f be the focal distance for the entire lens system and ff2 the focal distance for the second group lens, 1.0?ff2/f?2.0 is satisfied; therefore, the entire length of the lens system can be kept short and image curvature can be suppressed. In addition, each of the subject side lens surfaces and the image side lens surfaces for the second group lens, third group lens, and fourth group lens are provided with aspherical surface shapes; therefore, the imaging lens is constituted to be bright.