Abstract: A reflective type passive infrared motion detection system includes a housing, a sensor element and a reflecting element. The sensor element is disposed on the housing. The reflecting element is disposed on the housing and has a plurality of reflecting tiers. Each reflecting tier has a plurality of reflecting curved surfaces, the reflecting curved surfaces are arranged along a first axial direction in sequence, and the reflecting tiers are arranged along a second axial direction in sequence. The reflecting curved surfaces respectively have different azimuth angles. An aperture width of each reflecting curved surface along a direction perpendicular to the second axial direction is positively correlated with a reciprocal of a cosine value of the corresponding azimuth angle. An aperture length of the reflecting curved surfaces of each tier along a direction of the second axial direction is positively correlated with square of a distance of the corresponding infrared source.

Abstract: A reflective type passive infrared motion detection system includes a housing, a sensor element and a reflecting element. The sensor element is disposed on the housing. The reflecting element is disposed on the housing and has a plurality of reflecting tiers. Each reflecting tier has a plurality of reflecting curved surfaces, the reflecting curved surfaces are arranged along a first axial direction in sequence, and the reflecting tiers are arranged along a second axial direction in sequence. The reflecting curved surfaces respectively have different azimuth angles. An aperture width of each reflecting curved surface along a direction perpendicular to the second axial direction is positively correlated with a reciprocal of a cosine value of the corresponding azimuth angle. An aperture length of the reflecting curved surfaces of each tier along a direction of the second axial direction is positively correlated with square of a distance of the corresponding infrared source.

Abstract: A telephoto zoom lens include a first, a second, a third and a fourth lens groups sequentially arranged along an optical axis and from an object side to an image side. The refractive powers of the four lens groups are positive, negative, positive and positive, respectively. The first lens group is fixed at a first predetermined position. The second lens group is movable along the optical axis depending on the variation of the magnifying power of the zoom lens. The third lens group is fixed at a second predetermined position. The fourth lens group is movable along the optical axis to keep an image plane generated by the zoom lens to project accurately onto an image sensor. Hence, the first and the third lens groups are in resting state, and the second and the fourth lens groups are movable during zoom-in or zoom-out operation of the zoom lens.

Abstract: A miniature zoom lens includes a first, a second and a third lens groups arranged along an optical axis and from an object side to an image side in sequence. The refractive powers of the three lens groups are negative, positive and positive, respectively. The first lens group is fixed at a predetermined position. The second lens group is movable along the optical axis in accordance with a change of magnification. The third lens group is movable along the optical axis for keeping an image plane fixed at an image sensor. The first lens group is in resting state and the second and the third lens groups are movable during zoom-in or zoom-out operation of the miniature zoom lens. In addition, the miniature zoom lens can be composed of at least seven pieces of lens, thus the cost is reduced, the manufacture is easy and the assembly is simple.

Abstract: A miniature zoom lens includes a first, a second and a third lens groups arranged along an optical axis and from an object side to an image side in sequence. The refractive powers of the three lens groups are negative, positive and positive, respectively. The first lens group is fixed at a predetermined position. The second lens group is movable along the optical axis in accordance with a change of magnification. The third lens group is movable along the optical axis for keeping an image plane fixed at an image sensor. The first lens group is in resting state and the second and the third lens groups are movable during zoom-in or zoom-out operation of the miniature zoom lens. In addition, the miniature zoom lens can be composed of at least seven pieces of lens, thus the cost is reduced, the manufacture is easy and the assembly is simple.