Abstract: A windshield corrective optical system includes a motor vehicle having a windshield. A camera is positioned within an occupant compartment of the motor vehicle directed toward the windshield and receiving light rays passing through the windshield. A sensor is configured to receive the light rays. A corrective element is configured to allow passage of the light rays through the corrective element to the sensor. The corrective element corrects aberrations of the light rays induced by passing through the windshield prior to the light rays reaching the sensor.

Abstract: A time of flight (ToF) camera according to embodiments of the present invention includes a light source unit including an infrared light-emitting device array and configured to generate a light signal; a lens unit disposed on the light source unit and including a plurality of lenses; and an adjustment unit configured to adjust the lens unit such that a light pattern of the light signal, which has passed through the lens unit, becomes a surface lighting or a spot lighting including a plurality of spot patterns, wherein the lens unit has a distortion aberration in the form of barrel distortion in which irradiance of the light pattern decreases in a direction away from a central portion.

Abstract: A dual-aperture zoom camera comprising a Wide camera with a respective Wide lens and a Tele camera with a respective Tele lens, the Wide and Tele cameras mounted directly on a single printed circuit board, wherein the Wide and Tele lenses have respective effective focal lengths EFLW and EFLT and respective total track lengths TTLW and TTLT and wherein TTLW/EFLW>1.1 and TTLT/EFLT<1.0. Optionally, the dual-aperture zoom camera may further comprise an optical OIS controller configured to provide a compensation lens movement according to a user-defined zoom factor (ZF) and a camera tilt (CT) through LMV=CT*EFLZF, where EFLZF is a zoom-factor dependent effective focal length.

Abstract: An imaging lens may be a retrofocus type imaging optical system including, in order from an object side, a first lens group, an aperture and a second lens group. The first lens group may include, from the object side, a meniscus as a first lens in which a convex surface is formed on the object side, and a meniscus lens as a second lens in which a convex surface is formed on the object side. The second lens group may include a convex lens as a third lens, a biconvex lens as a fourth lens, a biconvex lens as a fifth lens and a sixth lens, and the fifth lens and the sixth lens may be joined to each other. The imaging lens may be constructed with 6 elements and 5 groups including the first lens group and the second lens group.

Abstract: An imaging lens includes a positive first lens group and a second lens group, which are continuous in order from the position closest to the object side, as lens groups. During focusing, the distance between the first lens group and the second lens group changes. A stop is disposed closer to the image side than a lens which is second from the object side. A combined refractive power of all lenses closer to the object side than the stop is positive. The imaging lens includes an LA positive lens and an LB positive lens that satisfy a predetermined conditional expression at a position closer to the object side than the stop. An Abbe number of the LB positive lens is the maximum among Abbe numbers of all positive lenses closer to the object side than the stop.

Abstract: An optical assembly for a point action camera with a wide field of view includes multiple lens elements configured to provide a field of view in excess of 150 degrees. One or more lens elements has an aspheric surface. The optical assembly exhibits a low inward field curvature of less than 75 microns.

Abstract: Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises five lens elements positioned sequentially from an object side to an image side. Through controlling the convex or concave shape of the surfaces and/or the refracting power of the lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

Abstract: An imaging lens system and an imaging device capable of capturing a long-distance image in a central direction of an optical axis with high resolution and capturing a neighborhood image at a wide angle. An imaging lens system includes, in order from an object side: a first lens group including at least a first lens, a second lens, and a third lens; an aperture stop (STOP); and a second lens group including two or more lens and having a positive combined power, an image side of the first lens has a concave surface, a combined focal length of the first lens and the second lens is negative, the third lens is a lens having a positive power, an object side of the first lens has an aspherical surface, and an incident-side surface (object side) of the first lens has an inflection point.

Abstract: The present invention relates to an objective for photographic applications, comprising, in a sequence from an object side end to an image side end, a first lens group having a positive refractivity with at least one lens, a second lens group having a negative refractivity with a single lens, a third lens group having a negative refractivity with a single lens and a fourth lens group having a positive refractivity with at least one lens, wherein the lenses of the second and third lens groups each have a concave surface which face one another and define an air lens, wherein f1 is the overall focal length of the lenses of the second and third lens groups and f2 is the focal length of the air lens, and wherein the relationship 5.0?f1/f2?9.0 is true.

Abstract: An optical system LO includes in this order from an object side to an image side, a first lens unit FL, an aperture stop SP, and a second lens unit RL having a positive refractive power. The first lens unit FL includes at least three negative lenses including in order from the object side to the image side, negative lenses (G1N), (G2N), and (G3N). At least one lens surface of the negative lenses (G1N), (G2N), and (G3N) is an aspherical surface that satisfies a predetermined conditional inequality.

Abstract: An objective lens for an endoscope consists of a first lens group that consists of a negative lens, a second lens group that consists of a negative lens, a third lens group that consists of a cemented lens, an aperture stop, a fourth lens group that consists of a single lens having positive refractive power or a cemented lens having positive refractive power as a whole, and a fifth lens group that consists of a cemented lens including two lenses having refractive power having signs different from each other and cemented to each other; and the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group are arranged in this order from an object side toward an image side. The objective lens for an endoscope satisfies a predetermined conditional expression related to the cemented lenses.

Abstract: An optical system for rigid endoscope includes an objective optical system, an eyepiece optical system, and a relay optical system which is disposed between the objective optical system and the eyepiece optical system. The objective optical system includes in order from an object side, a first lens having a negative refractive power, a second lens having a positive refractive power, a third lens having a positive refractive power, and a fourth lens having a negative refractive power. The following conditional expressions (1) and (2) are satisfied: ?3<(RL1i+RL1o)/(RL1i?RL1o)<?1.3??(1) 30<?dL1??(2) where, RL1o denotes a radius of curvature of an object-side surface of the first lens, RL1i denotes a radius of curvature of an image-side surface of the first lens, and ?dL1 denotes Abbe number for the first lens.

Abstract: Various embodiments include a camera with folded optics. Some embodiments include a voice coil motor (VCM) actuator module to provide autofocus (AF) and/or optical image stabilization (OIS) movement. Some embodiments include suspension arrangements. Some embodiments include flexure arrangements.

Abstract: An optical lens comprises: a first lens having a negative focal power; a second lens; a third lens; a fourth lens; a fifth lens, wherein the fourth lens and the fifth lens forms an achromatic lens group; and a sixth lens, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are sequentially disposed along a direction from an object side to an image side, wherein the first lens has at least one object surface facing the object side, and the object surface of the first lens is convex, and wherein the second lens has at least one image surface facing the image side, and the image surface of the second lens is convex so as to facilitate forming a concentric circle structure.

Abstract: The present disclosure discloses an imaging lens assembly, the imaging lens assembly having a total effective focal length f and comprising sequentially, along an optical axis 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. Each of the first lens and the fifth lens has a negative focal power; each of the second lens, the fourth lens, the sixth lens and the seventh lens has a positive focal power or a negative focal power; and the third lens has a positive focal power, and an effective focal length f3 of the third lens and the total effective focal length f satisfy: 1<f3/f<1.5.

Abstract: The imaging lens consists of, in order from an object side, a negative first lens group immovable during focusing, a stop and a positive second lens group moving during focusing. The first lens group consists of, in order from the object side, a meniscus lens having a convex surface toward the object side, a negative meniscus lens having a convex surface toward the object side, a negative lens, a biconvex lens, a negative meniscus lens having a convex surface toward the object side, and a positive lens having a convex surface toward the object side. Predetermined conditional expressions concerning a focal length f of the entire system, a focal length f1 of the first lens group, and a shape of an air lens between first and second lenses of the first lens group from an image side are satisfied.

Abstract: An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; a fourth lens having positive refractive power; a fifth lens; a sixth lens; a seventh lens; an eighth lens; and a ninth lens having negative refractive power, arranged in this order from an object side to an image plane side. The ninth lens is formed in a shape so that a surface thereof on the image plane side has an aspherical shape having an inflection point.

Abstract: An optical system according to the present invention is an optical system consisting of a front lens group having a positive or negative refractive power, an aperture stop, and a rear lens group having a positive or negative refractive power that are placed in order from an object side to an image side. In the optical system, relationships between a distance on an optical axis between a negative lens having the strongest refractive power in the rear lens group and a positive lens placed on the image side of the negative lens, an opening angle of the positive lens, a back focus of the optical system, and a focal length of the optical system are appropriately determined.

Abstract: An optical imaging system includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens having a negative refractive power, and a fifth lens having a positive refractive power. The first to fifth lenses are sequentially disposed from an object side to an imaging plane. One or more lenses among the first to fifth lenses are formed using a glass material.

Abstract: The imaging optical system is provided with a first lens having a negative refractive power, a second lens having a positive refractive power, an aperture stop, and a third lens having a positive refractive power, disposed from the object side to the image side. With |d| being the distance between the image-side principal point of the first lens and the object-side principal point of the second lens, d=?|d| being the signed distance between the image-side principal point of the first lens and the object-side principal point of the second lens when the image-side principal point of the first lens is further towards the image side than the object-side principal point of the second lens, and f12 being the composite focal length of the first lens and the second lens, the relationships d<0 and 0.005<d/f12<16 are established.

Abstract: An image-forming lens includes, from an object side to an image side in order: a first lens group; an aperture; and a second lens group with a positive refractive power, the first lens group including, from the object side in order: a first F lens group with a negative refractive power; and a first R lens group with a positive refractive power, the first F lens group including, from the object side in order: a first negative lens; and a second negative lens, and the first R lens group including: any one of a positive lens and a cemented lens with a positive refractive power as a whole, wherein a distance from a surface on a most object side of the first lens group to an image plane in a state of focusing on an object at infinity: L, and a maximum image height: Y? satisfy Conditional expression 1: 2.8<L/Y?<4.3.

Abstract: The technology provides decoupling an aspheric optical element from a birdbath optical element in a near-eye display (NED) device. One or more aspheric lens are used with a spherical birdbath reflective mirror in a projection light engine of a NED device. A projection light engine provides image light (or other information), by way of the spherical birdbath reflective mirror and at least one aspheric lens, to a near-eye display of the NED device. The spherical birdbath reflective mirror collimates and reflects the image light to an exit pupil external to the projection light engine. Decoupling the aspheric optical element from the spherical birdbath reflective mirror may enable high modulation transfer function (MTF) and improved manufacturability of the projection light engine. The NED device having aspheric optical elements decoupled from a birdbath optical element may be positioned by a support structure in a head-mounted display (HMD) or head-up display (HUD).

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 has a modulation transfer function (hereinafter “MTF”) at the Nyquist frequency that is above 0.3 and a MTF at half Nyquist frequency that is above 0.5 across the wide field of view.

Abstract: There is provided an imaging lens with high-resolution which satisfies, in well balance, demand of the wide field of view, the low-profileness and the low F-number and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having negative refractive power, a second lens, a third lens, a fourth lens, and a fifth lens, wherein said second lens has the negative refractive power, and below conditional expressions are satisfied: 0.1<T2/T3<1.16 9<r3/r4<20 ?0.1<r5/r6<1.

Abstract: A seven-lens wide-angle camera lens, having: a first lens with a negative refractive power; a second lens with a negative refractive power; a third lens with a refractive power; a fourth lens with a positive refractive power; a fifth lens with a refractive power; a sixth lens with a refractive power; and a seventh lens with a refractive power; and satisfies the following relational expressions: 0.06<CT3?TTL<0.15; and ?0.7<f6/f7<?0.2; wherein, CT3 is a center thickness of the third lens that is on an optical axis; TTL is an axial distance from an object side surface to an imaging plane of the first lens; f6 is an effective focal length of the sixth lens; and f7 is an effective focal length of the seventh lens. By reasonably combining the 7 lenses, can obtain large field angles, which realizes miniaturization and favorable manufacturability while ensuring high resolution and imaging quality.

Abstract: The invention discloses a six-piece optical lens for capturing image and a six-piece optical module for capturing image. In order from an object side to an image side, the optical lens along the optical axis comprises a first lens with refractive power; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power; a fifth lens with refractive power; a sixth lens with refractive power; and at least one of the image-side surface and object-side surface of each of the six lenses is aspheric. The optical lens can increase aperture value and improve the imagining quality for use in compact cameras.

Abstract: An optical image assembly includes six 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 and a sixth lens element. The second 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. The third lens element has positive refractive power. The fourth lens element has positive refractive power. The fifth lens element has positive refractive power. The sixth lens element has negative refractive power.

Abstract: A six-piece optical lens for capturing image and a six-piece optical module for capturing image are provided. In order from an object side to an image side, the optical lens along the optical axis includes a first lens with refractive power, a second lens with refractive power, a third lens with refractive power, a fourth lens with refractive power, a fifth lens with refractive power and a sixth lens with refractive power. At least one of the image-side surface and object-side surface of each of the six lens elements is aspheric. The optical lens can increase aperture value and improve the imagining quality for use in compact cameras.

Abstract: The number of lenses within an objective lens for endoscopes is only three. The objective lens for endoscopes includes, in order from the object side, a first lens which is a single lens having a negative refractive power and a concave surface toward the object side, an aperture stop, and a cemented lens. The cemented lens is formed by cementing one positive lens and one negative lens together. Conditional formulae related to the distance from the surface toward the object side of the first lens to the aperture stop and the Abbe's numbers of the positive lens and the negative lens that constitute the cemented lens are satisfied.

Abstract: An imaging lens includes a first lens group; a second lens group; and a third 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 fourth lens and a fifth lens having negative refractive power. The third lens group includes a sixth lens having negative refractive power and a seventh lens.

Abstract: An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens, disposed in order from an object side to an imaging plane. One or any combination of the first lens to the seventh lens are formed of glass. One or both surfaces of one or more of the first lens to the seventh lens are aspherical. A pair of lenses, among the first lens to the seventh lens, allows paraxial areas opposing each other to be bonded to each other.

Abstract: An optical device has a visible light transmittance that decreases from a central part thereof towards a peripheral part thereof. The optical device includes a visible light absorbing part, made of a material that absorbs at least a part of visible light, and having a thickness that increases from a central part thereof towards a peripheral part thereof, and a visible light transmitting part, made of a material that transmits the visible light, and is stacked on the visible light absorbing part. A relationship T420/T360>=3 is satisfied, where T420 denotes a transmittance of light having a wavelength of 420 nm, and T360 denotes a transmittance of light having a wavelength of 360 nm.

Abstract: A single focal imaging optical system includes, in order from an object side, a first lens group with a positive power, an aperture stop, and a second lens group with a positive power. The first lens group includes a first front lens group and a first rear lens group. The first front lens group includes a negative lens having a concave surface on an image side and a positive meniscus lens having a concave surface on the object side. The first rear lens group includes a biconvex lens. The second lens group includes a second front lens group with a negative power and a second rear lens group with a positive power. The system satisfies a following condition: 3.2<f2/f1<9.0, where f1 represents a composite focal length of the first lens group and f2 represents a composite focal length of the second lens group.

Abstract: An image-forming lens includes, from an object side to an image side in order: a first lens group; an aperture; and a second lens group with a positive refractive power, the first lens group including, from the object side in order: a first F lens group with a negative refractive power; and a first R lens group with a positive refractive power, the first F lens group including, from the object side in order: a first negative lens; and a second negative lens, and the first R lens group including: any one of a positive lens and a cemented lens with a positive refractive power as a whole, wherein a distance from a surface on a most object side of the first lens group to an image plane in a state of focusing on an object at infinity: L, and a maximum image height: Y? satisfy Conditional expression 1: 2.8<L/Y?<4.3.

Abstract: Present embodiments provide for an optical imaging lens. The optical imaging lens comprises a first lens element, a second lens element, a third lens element and a fourth lens element positioned in an order from an object side to an image side. Through controlling the convex or concave shape of the surfaces of the lens elements and designing parameters satisfying at least one inequality, the optical imaging lens shows better optical characteristics and enlarge field angle while the total length of the optical imaging lens is shortened.

Abstract: An optical lens 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 has refractive power. The third lens element has positive refractive power. The fourth lens element with positive refractive power has an image-side surface being convex in a paraxial region thereof. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof and including one convex shape in an off-axial region thereof. The sixth lens element with refractive power has an image-side surface being concave in a paraxial region thereof and including one convex shape in an off-axial region thereof.

Abstract: An imaging lens includes a first lens group having positive refractive power and a second lens group having negative refractive power, arranged in this order from an object side to an image plane side. The first lens group includes a first lens having positive refractive power, a second lens having negative refractive power, and a third lens. The second lens group includes a front side lens group having negative refractive power and a rear side lens group having positive refractive power. 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. The first lens group is arranged to be away from the second lens group by a specific distance on an optical axis thereof. The first to third lenses have specific Abbe's numbers.

Abstract: Provided is an optical system, including, in order from an object side to an image side: a front group having a negative refractive power; an aperture stop; and a rear group having a positive refractive power, in which: the front group consists of in order from the object side to the image side: a negative first lens (L1) having a concave surface facing the image side; a second lens (L2); and a third lens (L3); the rear group consists of, in order from the object side to the image side: a positive fourth lens (L4); and a negative cemented lens (L56), which is obtained by cementing a positive fifth lens (L5) and a negative sixth lens (L6); and a focal length f56 of the cemented lens (L56) and a focal length f of the optical system are each appropriately set.

Abstract: The imaging lens consists essentially of a front group that consists essentially of a negative first lens having a meniscus shape with a convex surface toward the object side, a negative second lens and a positive third lens; a stop; a positive rear group that consists essentially of one positive lens and one negative lens. When the Abbe number with respect to the d-line of the material of the first lens is ?d1 and the refractive index thereof is Nd1 , conditional formula (1) below is satisfied: 60.0<?d1+26*Nd1<85.0??(1).

Abstract: A small-sized objective optical system for an endoscope having in order from an object side, a first negative lens which is planoconcave, a second meniscus lens having a convex surface directed toward an image side, a third positive meniscus lens having a convex surface directed toward the object side, a positive lens unit, and a cemented lens in which, a positive lens and a negative lens are cemented. Focusing is carried out by moving the third positive meniscus lens along an optical axis, and the second meniscus lens is a negative lens.

Abstract: An ultrasonic transmitting and receiving device is provided for measuring the transmission and/or reflection of ultrasonic waves on a thin material sheet, or a coating applied thereto. The device may include a plurality of ultrasonic transmitters, a plurality of ultrasonic receivers, wherein the number of the ultrasonic transmitters corresponds to the number of the ultrasonic receivers, and one receiver electronics respectively for each of the ultrasonic receivers or a group receiver electronics respectively for a predetermined number of ultrasonic receivers. A method is provided for ultrasonic absorption and/or transmission measurement, in which signals are emitted by multiple ultrasonic transmitters at the same time or nearly at the same time which are received by ultrasonic receivers and in which the received signals are evaluated in parallel.

Abstract: A compact low-priced imaging lens which offers a field of view of about 180 degrees and high optical performance. The imaging lens for a solid-state image sensor includes, in order from an object side to an image side, a first lens with negative refractive power having a convex object-side surface and an aspheric image-side surface; a second lens with negative refractive power as a double-sided aspheric lens having a concave surface on the image side; a third lens with positive refractive power; an aperture stop; and a fourth lens with positive refractive power. The first and second lenses are made of plastic material. The imaging lens satisfies conditional expressions (1) and (2) below: ?65.0<f1/f<?17.0??(1) 0.04<f2/f1<0.14??(2) where f: focal length of the overall optical system of the imaging lens f1: focal length of the first lens f2: focal length of the second lens.

Abstract: An imaging lens provided with a negative first lens group and a positive second lens group disposed in order from the object side. The first lens group is composed of a first group first lens which is a biconcave negative single lens, and the second lens group is composed of a positive second group first lens, an aperture stop, a positive second group second lens, and a negative second group third lens disposed in order from the object side. The second group second lens and second group third lens are cemented to form a cemented lens. The imaging lens is configured to satisfy conditional expressions (2): 0<fg2/f<1.3, (2b?): 0.5<fg2/f<1.25, and (6): 31<?d2 <70 at the same time, where fg2 is combined focal length of the second lens group, f is focal length of the entire lens system, and ?d2 is Abbe number of the second group first lens.

Abstract: An imaging apparatus includes: a first lens group disposed on a subject side of a diaphragm in the vicinity of which two polarizers that polarize light from a subject are disposed, the polarizers being first and second polarizers whose polarization directions are perpendicular to each other; a second lens group disposed on the side of the diaphragm where an imaging device is present, over a photodetection surface of which third and fourth polarizers are disposed, the third and fourth polarizers having polarization directions parallel to the polarization direction of the first and second polarizers, respectively; and an image processor that produces stereoscopic images based on image data produced by converting light incident on the imaging device through the first lens group and the second lens group. The second lens group has positive refracting power, and characteristics of the first lens group and the second lens group satisfy certain conditions.

Abstract: There are provided an imaging optical system and imaging equipment, which are compatible with a solid-state imaging device having a size of ½ inches or less and which include an optical system having a small size and lightness in weight and also having an excellent mass productivity and a low cost while keeping optical performance at a wide field angle, for example, at a total angle of view of 80 degrees or more. When predetermined conditions are satisfied for a plurality of lenses constituting the imaging optical system, the absolute value of power of each lens group is suppressed to be small, and thus the generation of aberration is suppressed and a preferable aberration is obtained.

Abstract: An imaging lens is composed of a first lens having a negative meniscus shape with a convex surface on the object side, a negative second lens, a positive third lens, an aperture stop, a negative fourth lens, and a positive fifth lens disposed in order from the object side. The fourth and the fifth lens are cemented with an interface which is convex on the object side and has an aspherical shape. If the radius of curvature is taken as R9 and the focal length of the entire system is taken as f, the imaging lens satisfies a conditional expression given below: 1.0<R9/f??(1).

Abstract: An objective optical system includes: a negative first lens group; an aperture stop; and a positive second lens group, provided in this order from an object side. The first lens group includes a first lens, which is a negative single lens, and a cemented lens formed by cementing a positive lens and a negative lens together, provided in this order from the object side. The second lens group includes a fourth lens, which is a positive single lens, and a cemented lens formed by cementing a positive lens and a negative lens together, provided in this order from the object side. The objective optical system satisfies Conditional Formula (1): f1/f<1.1, wherein f1 is the focal length of the lens provided most toward the object side, and f is the focal length of the entire lens system.

Abstract: A zoom lens includes: a first lens group having a negative power; and a second lens group having a refractive power, in this order from an object side. The zoom lens satisfies the following conditional formulae: 1.0<D2g/D1g<1.6, 0.08<D2t/ft<0.19, 1.15?ft/|f1|<1.8, and 1.1<ft/f2<1.9, wherein D1g is the distance from a most object side lens surface to a most image side lens surface within the first group, D2g and D2t are the distance from a most object side lens surface to a most image side lens surface within the second group and the distance between an object side partial second lens group and an image side partial second lens group when focused on infinity at a telephoto end, respectively, ft is the focal length of the entire system at the telephoto end, and f1 and f2 are the focal lengths of the first group and the second group, respectively.

Abstract: An imaging lens includes a first lens group having negative refractive power; a stop; and a second lens group having positive refractive power, arranged in the order from the object side to the image plane side. The first lens group includes a first lens having a strong concave surface facing the image plane side and negative refractive power; and a second lens having negative refractive power and a biconcave lens shape near the optical axis. The second lens group includes a third lens having a biconvex shape; and a lens group that is composed of a lens having positive refractive power and a lens having negative refractive power, and has negative refractive power as a whole. The first lens group has a focal length F1 and the second lens group has a focal length F2 so that the following conditional expression is satisfied: ?1.0<F1/F2<?0.5.

Abstract: An imaging lens formed of 4 lenses, in which a negative first lens having a meniscus shape with a convex surface on the object side, a biconvex positive second lens, a negative third lens having a concave surface on the image side, and a positive fourth lens having a convex surface on the object side, arranged in order from the object side, and the imaging lens satisfies conditional expressions (1): L12/f<0.82; (2): 2.3<L12×R2F2/f2<10.0; (5): ?1.3<f1/f<?0.9; and (6): 48<v1 simultaneously, where, L12 is the air equivalent distance between the first lens and the second lens, f is the focal length of the entire lens system, R2F is the radius of curvature of the object side lens surface of the second lens, f1 is the focal length of the first lens, and v1 is the Abbe number of the first lens with respect to the d-line.