Abstract: A heat sink installing device includes a base, a pair of guiding poles, a slidable cover, a pair of latches and a number of auxiliary wings. The pair of guiding poles is perpendicularly mounted on the base and separated from each other. The slidable cover is slidably fitted on the pair of guiding poles and defines a pair of through holes running through two opposite side surfaces of the slidable cover. Each of the latches is mounted on the slidable cover and latched on one of the guiding poles correspondingly. The plurality of auxiliary wings are correspondingly attached on a side surface of the slidable cover around the through hole and inclined towards the center of the through hole by a distal end thereof away from the slidable cover.

Abstract: The present disclosure relates to a wide angle lens system. The wide angle lens system includes, in order from the object side to the image side thereof, a first lens of positive refraction power, a second lens of positive refraction power, and a third lens of negative refraction power. The wide angle lens system satisfies the following condition: 0.45<f/TTL<0.75; and 1.4<f1/f<2.4. Wherein, TTL is a distance from a surface of the first lens facing the object side of the wide angle lens system to an image plane, f is a focal length of the wide angle lens system, and f1 is a focal length of the first lens.

Abstract: The present disclosure relates to a wide angle lens system. The wide angle lens system includes, in order from the object side to the image side thereof, a first lens of positive refraction power, a second lens of positive refraction power, and a third lens of negative refraction power. The wide angle lens system satisfies the following condition: 0.45<f/TTL<0.75; and 1.4<f1/f<2.4. Wherein, TTL is a distance from a surface of the first lens facing the object side of the wide angle lens system to an image plane, f is a focal length of the wide angle lens system, and f1 is a focal length of the first lens.

Abstract: An imaging lens includes an imaging lens system and an image sensor. The imaging lens system includes a first lens, a second lens, a third lens, and a fourth lens. The imaging module satisfies the formulas (1) D/T?1.1, (2) ?3.5<R2/F1<?1.5, (3) ?2.5<R3/F2<?0.5, and (4) 1.5<|R7/F4|<3.5, wherein D is the diagonal length of the sensing area of the image sensor, T is the length from the object surface of the first lens to the sensing surface of the image sensor, R2 is the radius of curvature of the image side surface of the first lens, R3 is the radius of curvature of the object side surface of the second lens, R7 is the radius of curvature of the object side surface of the fourth lens, F1, F2, F4 are the corresponding focal length of the first lens, the second lens, and the third lens.

Abstract: A heat sink installing device includes a base, a pair of guiding poles, a slidable cover, a pair of latches and a number of auxiliary wings. The pair of guiding poles is perpendicularly mounted on the base and separated from each other. The slidable cover is slidably fitted on the pair of guiding poles and defines a pair of through holes running through two opposite side surfaces of the slidable cover. Each of the latches is mounted on the slidable cover and latched on one of the guiding poles correspondingly. The plurality of auxiliary wings are correspondingly attached on a side surface of the slidable cover around the through hole and inclined towards the center of the through hole by a distal end thereof away from the slidable cover.

Abstract: An infrared imaging lens system includes, in the order from the object side to the image side thereof, a first lens with negative refractive power, a second lens with positive refractive power and a third lens with positive refractive power. The infrared imaging lens system satisfies the following formulas: ?0.65<F/F1<?0.55, 0.52<F/F2<0.62, 0.3<|F/F3|<0.6, where F1, F2 and F3 are the focal lengths of the first lens, the second lens and the third lens correspondingly, and F is the focal length of the infrared imaging lens system.

Abstract: An imaging module includes an imaging lens system and an image sensor. The imaging lens system includes a first lens, a second lens, and a third lens. The imaging module satisfies the formulae, 2.4<S1/D1<3.0, 0.3<R1/F<0.7, wherein S1 is the effective diameter of the first surface S1 of the first lens, D1 is the distance from the object side surface S1 to the image side surface S2 of the first lens along the optic axis, R1 is the radius of curvature of the object side surface S1 of the first lens, and F is the focal length of the imaging lens system.

Abstract: An imaging lens includes an imaging lens system and an image sensor. The imaging lens system includes a first lens, a second lens, a third lens, and a fourth lens. The imaging module satisfies the formulae (1) D/T?1.1, (2) ?3.5<R2/F1<?1.5, (3) ?2.5<R3/F2<?0.5, and (4) 1.5<|R7/F4|<3.5, wherein D is the diagonal length of the sensing area of the image sensor, T is the length from the object surface of the first lens to the sensing surface of the image sensor, R2 is the radius of curvature of the image side surface of the first lens, R3 is the radius of curvature of the object side surface of the second lens, R7 is the radius of curvature of the object side surface of the fourth lens, F1, F2, F4 are the corresponding focal length of the first lens, the second lens, and the third lens.

Abstract: An imaging lens includes, in the order from the object side to the image side, 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 formulae (1) 1<T/F<1.4; (2) R3/F>4; and (3) S1/S2>3, where T is the overall length of the imaging lens, F is the focal length of the imaging lens, R3 is the radius of curvature of the object-side surface of the second lens, S1 is the vertical distance from the edge to the center of the image-side surface of the third lens, and S2 is the horizontal distance from the edge to the center of the image-side surface of the third lens.