Abstract: An optical module comprising: at least three lens elements, wherein the lens elements collectively set a numerical aperture NA, a field height FH, and a system effective focal length EFLsys for directing the light rays between first and second planes, wherein NA, FH, and EFLsys satisfy 0<NA<0.25 and 0<FH<(0.4)·(EFLsys); wherein first and second adjacent lens elements having effective focal lengths EFL1 and EFL2, respectively, satisfies (1.5)·(EFLsys)<EFL1<3·(EFLsys) and (1.5)·(EFLsys)<EFL2<3·(EFLsys); wherein an air-distance between the first and second lens elements A12 satisfies 0<A12<EFLsys; wherein a third lens element adjacent the second lens elements opposite the first lens element and having an effective focal length EFL3 satisfies (?20)·EFLsys<EFL3<(?1)·EFLsys; and wherein an air-distance between the second and third lens elements A23 satisfies 0<A23<EFLsys.

Abstract: The present disclosure discloses an optical imaging lens assembly, which includes sequentially from an object side to an image side along an optical axis, a first lens and at least one subsequent lens having refractive power. A distance TTL along the optical axis from an object-side surface of the first lens to an image plane of the optical imaging lens assembly and a distance P along the optical axis from a to-be-captured object to the object-side surface of the first lens satisfy 0.6<TTL/P*10<1.8.

Abstract: Provided are a laser cutting device and a laser cutting method. The laser cutting device comprises a beam expanding element provided with a plurality of lens sets, wherein optical axes of the plurality of lens sets are located in the same line and each lens set comprises at least one lens; the beam expanding element is configured to convert an incident beam into a first beam; and a spectroscopic element arranged on a light path of an emitted light of the beam expanding element, and wherein the spectroscopic element is configured to convert the first beam into multiple second beams that are annular and spaced apart from each other.

Abstract: The disclosure provides a zoom lens group, sequentially including, from an object side to an image side along an optical axis: a first lens group with positive refractive power, including a first lens with refractive power and a second lens with refractive power, which are sequentially arranged along the optical axis; a second lens group with negative refractive power, including a third lens with negative refractive power and a fourth lens with refractive power, which are sequentially arranged along the optical axis; and a third lens group with positive refractive power, including a fifth lens with positive refractive power, a sixth lens with refractive power, a seventh lens with negative refractive power and an eighth lens with refractive power, which are sequentially arranged along the optical axis, Positions of the second lens group and the third lens group on the optical axis are adjustable.

Abstract: An optical device comprises a first meta-lens and a second meta-lens. The first meta-lens includes a first plurality of nanostructures that define a first phase profile of the first meta-lens. The second meta-lens includes a second plurality of nanostructures that define a second phase profile of the second meta-lens. A combination of the first meta-lens having the first phase profile and the second meta-lens having the second phase profile is configured to achieve a diffraction-limited focusing and correct an aberration of light transmitted through the optical device.

Abstract: A lens system, a fingerprint identification module and a terminal device, including a first lens, a second lens and a third lens arranged sequentially from an object side to an image side, wherein the first lens is a meniscus negative optical power lens with the object side being concave, the second lens is a positive optical power lens with both object side and image side being convex, and the third lens is a positive optical power lens with both object side and image side being convex. The parameters of the lens system follow a first relationship so that a field of view FOV of the lens system is greater than a first threshold.

Abstract: A lens assembly includes a first lens, a second lens, and a third lens. The first lens is with negative refractive power and includes a concave surface facing an image side. The second lens is with positive refractive power and includes a convex surface facing the image side. The third lens is with positive refractive power and includes a convex surface facing an object side. The first lens, the second lens, and the third lens are arranged in order from the object side to the image side along an optical axis. The lens assembly satisfies the following condition: 3.5?R21/?8; wherein R21 is a radius of curvature of an object side surface of the second lens and f is an effective focal length of the lens assembly.

Abstract: Multi-cameras and in particular dual-cameras comprising a Wide camera comprising a Wide lens and a Wide image sensor, the Wide lens having a Wide effective focal length EFLW and a folded Tele camera comprising a Tele lens with a first optical axis, a Tele image sensor and an OPFE, wherein the Tele lens includes, from an object side to an image side, a first lens element group G1, a second lens element group G2 and a third lens element group G3, wherein at least two of the lens element groups are movable relative to the image sensor along the first optical axis to bring the Tele lens to two zoom states, wherein an effective focal length (EFL) of the Tele lens is changed from EFLT,min in one zoom state to EFLT,max in the other zoom state, wherein EFLTmin>1.5×EFLW and wherein EFLTmax>1.5×EFLTmin.

Abstract: The present disclosure discloses an optical imaging lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens having positive refractive power; a second lens having refractive power; a third lens having positive refractive power with a concave object-side surface and a convex image-side surface; a fourth lens having positive refractive power with a concave object-side surface and a convex image-side surface; and a fifth lens having refractive power. Half of a maximal field-of-view Semi-FOV of the optical imaging lens assembly satisfies: Semi-FOV>48°.

Abstract: An optical imaging lens assembly includes three lens elements which are, in order from an object side to an image side: a first lens element, a second lens element and a third lens element. Each of the three lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof. The object-side surface of the first lens element is aspheric and has at least one inflection point. The object-side surface of the first lens element has at least one critical point in an off-axis region thereof. The optical imaging lens assembly has a total of three lens elements.

Abstract: A camera optical lens is provided, including from an object side to an image side: a first lens having positive refractive power; a second lens having positive refractive power; and a third lens having negative refractive power, wherein the camera optical lens satisfies following conditions: 1.40?f1/f?2.00; 0.65?f2/f?0.90; ?1.50?f3/f??0.85; 2.50?d3/d4?10.00; and 2.00?(R5+R6)/(R5?R6)?4.50. The above camera optical lens can meet design requirements for large aperture, wide angle and ultra-thinness while maintaining good imaging quality.

Abstract: An optical lens assembly includes, in order from the object side to the image side: a stop, a first lens element, a second lens element, a third lens element, and an infrared bandpass filter. An entrance pupil diameter of the optical lens assembly is EPD, a half of a maximum field of view of the optical lens assembly is HFOV, and the following condition is satisfied: 0.59<EPD/tan(HFOV)<1.33.

Abstract: An imaging lens assembly module has an optical axis, and includes an optical element set, a light blocking element assembling surface, and a light absorbing layer. The optical element set includes an optical lens element and a light blocking sheet. The optical lens element is a plastic lens element, and includes an optical effective portion and an outer peripheral portion. The light blocking sheet is disposed on the outer peripheral portion, and spaced apart from the outer peripheral portion. The light blocking sheet includes an object-side surface, an image-side surface and an inner opening surface. The inner opening surface surrounds a through hole of the light blocking sheet. The light blocking sheet is disposed on the light blocking element assembling surface. The light absorbing layer is disposed on the image-side surface and for fixing the light blocking sheet on the light blocking element assembling surface.

Abstract: An optical image capturing lenses includes, in order from an object side to an image side, a front lens group, a stop, and a rear lens group. The front lens group includes, in order from the object side to the image side, at least a first lens element and a second lens element. The first lens element has a convex object-side surface and a concave image-side surface. The rear lens group includes, in order from the object side to the image side, at least a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element. The sixth lens element is made of plastic material. The object-side surface and the image-side surface of the sixth lens are aspheric. The sixth lens element has at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof.

Abstract: The present disclosure provides an optical imaging lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens having refractive power; a second lens having refractive power; and a third lens having refractive power. A distance BFL along the optical axis from an image-side surface of the third lens of the optical imaging lens assembly to an imaging plane of the optical imaging lens assembly and a distance Td along the optical axis from an object-side surface of the first lens to the image-side surface of the third lens satisfy: 4.5?BFL/Td?7.0.

Abstract: Disclosed is an optical lens, from an object side to an image side including a first lens, a second lens and a third lens. The camera optical lens satisfies: 1.20?f1/f?1.80; ?2.00?f2/f??1.00; 0.75?f3/f?1.10; ?6.00?R2/R1??2.00; 2.20?R4/R3?8.00; 1.50?d2/d4?3.50; where f, f1, f2 and f3 denote a focal length of the camera optical lens, the first lens, the second lens and the third lens, respectively; R1, R2 denote a central curvature radius of an object-side surface and an image-side surface of the first lens, respectively; R3, R4 denote a central curvature radius of an object-side surface and an image-side surface of the second lens, respectively; d2 denotes an on-axis distance from the image-side surface of the first lens to the object-side surface of the second lens, and d4 denotes an on-axis distance from the image-side surface of the second lens to an object-side surface of the third lens.

Abstract: An image capturing optical lens assembly includes three lens elements, the three lens elements being, in order from an object side to an image side along an optical path, a first lens element, a second lens element and a third lens element. Each of the three lens elements has an object-side surface towards the object side and an image-side surface towards the image side. The second lens element has negative refractive power. The object-side surface of the third lens element is concave in a paraxial region thereof, and the image-side surface of the third lens element is convex in a paraxial region thereof. The image capturing optical lens assembly has a total of three lens elements.

Abstract: An optical photographing lens assembly includes three lens elements which are, in order from an object side to an image side: a first lens element, a second lens element and a third lens element. Each of the three lens elements of the optical photographing lens assembly has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof, the object-side surface of the first lens element is aspheric and has at least one inflection point, and the object-side surface of the first lens element has at least one critical point in an off-axis region thereof. The optical photographing lens assembly has a total of three lens elements.

Abstract: An observation optical system for use in observing an image displayed on an image displaying surface, includes, in order from an observation surface side to the image displaying surface side: a first lens having a first transmission reflective surface and a first transmissive surface; and a second lens having a second transmission reflective surface and a second transmissive surface, in which the first lens and the second lens are arranged via an interval interposed therebetween; light from the image displaying surface transmits through the second lens, is reflected by the first transmission reflective surface, is reflected by the second transmission reflective surface, is transmitted through the first lens, and then travels toward the observation surface side; and a focal length of the first lens and a focal length of the observation optical system are appropriately set.

Abstract: An optical imaging lens assembly includes three lens elements which are, in order from an object side to an image side: a first lens element, a second lens element and a third lens element. Each of the three lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof. The object-side surface of the first lens element is aspheric and has at least one inflection point. The object-side surface of the first lens element has at least one critical point in an off-axis region thereof. The optical imaging lens assembly has a total of three lens elements.

Abstract: The present disclosure discloses an iris lens assembly. The iris lens assembly comprises sequentially a first lens, a second lens, a third lens and a filter from an object side to an image plane along an optical axis. An aperture diaphragm is arranged between the first lens and the second lens. The first lens has a positive refractive power, an object side surface of the first lens is a convex surface and an image side surface of the first lens is a concave surface. The second lens has a negative refractive power. The third lens has a positive refractive power or a negative refractive power. The filter is an infrared (IR) filter, and a bandpass wave band of the filter ranges from 750 nm to 900 nm.

Abstract: An imaging optical system includes a positive or negative first lens group, a diaphragm and a positive second lens group. The first lens group includes a positive lens element, provided closest to the object side, that has an aspherical surface on the object side thereof, the aspherical surface including a paraxial convex surface convexing toward the object side. This aspherical surface has a curvature that is positive along a meridional cross-section at the paraxial portion thereof, and the curvature of the meridional cross-section changes from a positive value to a negative value in an area within 75% of an effective aperture from the paraxial portion toward the periphery of the aspherical surface.

Abstract: A filter includes a central filter region, the central filter region to transmit a first wavelength range, a peripheral filter region, the peripheral filter region to block a second wavelength range, and a transition filter region between the central and peripheral filter regions, the transition filter region to transmit or block the second wavelength range differently than the second wavelength range is to be transmitted or blocked in the central and peripheral filter regions. More generally, there may be “N” regions and up to N-1 transition regions.

Abstract: The invention discloses a three-piece optical lens for capturing image and a three-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 positive refractive power; a second lens with refractive power; and a third lens with refractive power; and at least one of the image-side surface and object-side surface of each of the three lens elements are aspheric. The optical lens can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: Disclosed is a vehicle lamp including: a light source; and a projection lens that projects light emitted from the light source. The projection lens is constituted by a triplet lens including a first lens having a positive refractive power, a second lens having a negative refractive power, and a third lens having a positive refractive power, and a first inter-lens distance (t1) between the first lens and the second lens, a second inter-lens distance (t2) between the second lens and the third lens, and a total lens thickness (T) of the projection lens are in a relationship that satisfies 0.03<t1/T<0.1 and 0.03<t2/T<0.1.

Abstract: An image pickup apparatus includes an optical system which includes a plurality of lenses and an aperture stop, and an image sensor which is disposed at an image position of the optical system, wherein the optical system includes in order from an object side, a first lens having a negative refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, and a fourth lens, and the following conditional expressions (1) and (3) are satisfied: ?max??min<4.0×10?5/° C.??(1), and 0.2<D1Ls/DsF<3.0??(3).

Abstract: An optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element and a third lens element. The first lens element with positive refractive power has an object-side surface being convex, and the object-side surface and an image-side surface thereof are aspheric. The second lens element with negative refractive power has an image-side surface being concave, and an object-side surface and the image-side surface thereof are aspheric. The third lens element with refractive power has an object-side surface being concave, and the object-side surface and an image-side surface thereof are aspheric. The optical lens assembly further includes a stop with no lens element having refractive power disposed between the stop and the first lens element. The optical lens assembly has a total of three lens elements with refractive power.

Abstract: An image pickup apparatus includes an optical system which includes a plurality of lenses, and an image sensor which is disposed at an image position of the optical system, wherein the optical system includes in order from an object side, a first lens having a negative refractive power, an aperture stop, a second lens having a positive refractive power, and a third lens having a positive refractive power, and each of the first lens, the second lens, and the third lens is formed of a material having a refractive index not higher than 1.70, and the following conditional expressions (1), (2), (3), and (4) are satisfied: 0<f3/f2?1.7??(1), 0.5<?1L/IH<3.0??(2), 0.05<D1R2L/?d<0.5??(3), and ?0.4<f1/R1L<0.2??(4).

Abstract: A phase filter 101 is configured to comprise an annular structure rotationally symmetrical about an optical axis, each annular zone including a cross-sectional shape of substantially parabola for uniformly extending incident rays of light on a focal plane and letting the rays overlap with each other.

Abstract: An optical system includes, from an image side to an object side, a first lens having a positive refractive power, a second lens having a positive refractive power, and a third lens having a negative refractive power. The first lens, the second lens, and the third lens form an optical path with the object side facing a screen and the image side adapted to provide an image from the screen to a user. In one aspect, the optical system is adapted to correct at least one of a group of aberrations including astigmatism and field curvature; or, lateral color.

Abstract: A method for the laser-based machining of a sheet-like substrate, in order to separate the substrate into multiple portions, in which the laser beam of a laser for machining the substrate is directed onto the latter, is characterized in that, with an optical arrangement positioned in the path of rays of the laser, an extended laser beam focal line, seen along the direction of the beam, is formed on the beam output side of the optical arrangement from the laser beam directed onto the latter, the substrate being positioned in relation to the laser beam focal line such that an induced absorption is produced in the material of the substrate in the interior of the substrate along an extended portion, seen in the direction of the beam, of the laser beam focal line, such that a material modification takes place in the material of the substrate along this extended portion.

Abstract: The present disclosure provides a control method, a control device and an electronic device. The wide-angle camera is started first. Then, the displayer is controlled to display a cached wide-angle image as a preview image. Next, a designated area is identified and the telephoto camera is started during zooming the preview image. Further, the actuator is controlled such that a cached telephoto image is located in the designated area, and the wide-angle camera and telephoto camera are controlled to image respectively. Finally, the wide-angle image and telephoto image are combined. With the control method and device and the electronic device in the present disclosure, the telephoto camera may image the designated area when the user zooms the designated area of the cached wide-angle image, thereby enhancing sharpness of the designated area and improving the user experience.

Abstract: A six-aspheric-surface lens has six coaxially aligned lenses including, in order, a positive first lens, a negative second lens, a negative third lens, a negative fourth lens, a negative fifth lens, and a plano-gull-wing sixth lens. The six-aspheric-surface lens also includes a first biplanar substrate between the first lens and the second lens, a second biplanar substrate between the third lens and the fourth lens, and a third biplanar substrate between the fifth lens and the sixth lens. The first lens may have an Abbe number exceeding 48, the second lens and the third lens each may have an Abbe number less than 35. The first lens may have a focal length f1 and the second lens may have a focal length f2 such that ?0.27<f1/f2<?0.17. The six-aspheric-surface lens may have an effective focal length feff and a total track length T such that 0.9<T/feff<1.1.

Abstract: An infrared ray-tracing lens module is provided. The infrared ray-tracing lens module is adapted to receive light from an object. The infrared ray-tracing lens module includes a first positive diopter lens, a second positive diopter lens, a negative diopter lens and an image unit. The first positive diopter lens, the second positive diopter lens and the negative diopter lens are arranged along an optical axis, and the light travels from the object, sequentially passes through the first positive diopter lens, the second positive diopter lens and the negative diopter lens to be projected to the image unit.

Abstract: A lens module (50) and a 3D printer (100) comprising same. The lens module comprises a first lens (L1), a second lens (L2) and a third lens (L3) sequentially and coaxially arranged in the transmission direction of incident light. The first lens, the second lens and the third lens are all meniscus lenses. The first lens comprises a first curved surface (S1) and a second curved surface (S2). The second lens comprises a third curved surface (S3) and a fourth curved surface (S4). The third lens comprises a fifth curved surface (S5) and a sixth curved surface (S6). The first to the sixth curved surfaces are sequentially arranged in the transmission direction of the incident light, and the curvature radii of the first to the sixth curved surfaces are sequentially ?200±5%, ?100±5%, ?80±5%, ?150±5%, ?100±5% and ?70±5% in a unit of millimeter. By means of the lens module, the printing efficiency of the 3D printer is high and it is convenient to carry out printing of ultra-large workpieces.

Abstract: Wide angle fovea lens and a camera design using the lens are described. The lens has three lens groups and includes a single aspherical lens element. The lenses have higher magnification on the optical axis than at angles off the optical axis.

Abstract: Methods and apparatuses for stacking devices in an integrated circuit assembly are provided. A tray for supporting multiple dies of a semiconductor material enables both topside processing and bottom side processing of the dies. The dies can be picked and placed for bonding on a substrate or on die stacks without flipping the dies, thereby avoiding particulate debris from the diced edges of the dies from interfering and contaminating the bonding process. In an implementation, a liftoff apparatus directs a pneumatic flow of gas to lift the dies from the tray for bonding to a substrate, and to previously bonded dies, without flipping the dies. An example system allows processing of both top and bottom surfaces of the dies in a single cycle in preparation for bonding, and then pneumatically lifts the dies up to a target substrate so that topsides of the dies bond to bottom sides of dies of the previous batch, in an efficient and flip-free assembly of die stacks.

Abstract: An on-vehicle camera apparatus capturing an image in front of a vehicle includes: a camera module outputting image data and a control circuit board. The camera module includes an optical element that refracts incident light so as to diverge or focus the incident light, and an image sensor element in which incident light transmitted through the optical element forms an image. The control circuit board executes, based on the image data outputted by the camera module, a recognition process recognizing a state in front of the own vehicle, and also executes at least two vehicle control processes among a headlight control process, a forward collision preventing process and a lane departure warning process, as a result of the recognition process. According to the on-vehicle camera apparatus, a resin-made lens is used for the optical element.

Abstract: An ocular optical system includes a first lens element, a second lens element, and a third lens element from an eye-side to a display-side in order along an optical axis. The first lens element, the second lens element, and the third lens element each include an eye-side surface and a display-side surface. The first lens element has refracting power. The display-side surface of the second lens element has a convex portion in a vicinity of the optical axis. The third lens element has refracting power. The ocular optical system satisfies: T3/G23?4.3; and G3D/T3?3.51, where T3 is a thickness of the third lens element along the optical axis, G23 is an air gap from the second lens element to the third lens element along the optical axis, and G3D is a distance from the third lens element to the display screen along the optical axis.

Abstract: The invention discloses a three-piece optical lens for capturing image and a five-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 positive refractive power; a second lens with refractive power; and a third lens with refractive power; and at least one of the image-side surface and object-side surface of each of the three lens elements are aspheric. The optical lens can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: A fluorescence imaging system including a light source, an optical system, camera and an excitation light filter, the optical system produces a non-uniform fluence excitation illumination beam for illuminating an object and promoting fluorescence emissions, the optical system is positioned between the light source and the object, the optical system modifies the non-uniform fluence illumination beam into a uniform fluence illumination beam and changes the divergence of the uniform fluence illumination beam, the camera has an array of pixels, the camera detects the fluorescence emissions and performs pixel intensity measurements for each of the pixels, the excitation light filter is positioned between the object and the camera and filters out the excitation illumination beam, such that the excitation illumination beam does not reach the camera.

Abstract: The invention discloses a three-piece optical lens for capturing image and a five-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 positive refractive power; a second lens with refractive power; and a third lens with refractive power; and at least one of the image-side surface and object-side surface of each of the three lens elements are aspheric. The optical lens can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: A single focus lens and a photographing apparatus including the single focus lens are provided. The photographing apparatus includes a single focus lens comprising: a first lens group having a positive refractive power, the first lens group including a first negative lens and a second negative lens arranged in succession at a most object side of the first lens group; a second lens group having a negative refractive power; and a third lens group having a positive refractive power and including a positive lens and a negative lens. The first to third lens groups are sequentially arranged in a direction from an object side to an image side.

Abstract: The invention discloses a three-piece optical lens for capturing image and a three-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 positive refractive power; a second lens with refractive power; and a third lens with refractive power; and at least one of the image-side surface and object-side surface of each of the three lens elements are aspheric. The optical lens can increase aperture value and improve the imaging quality for use in compact cameras.

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

Abstract: Provided is an interactive lens assembly, including first lens, a second lens, an aperture stop, a third lens and a filter from an object side of the interactive lens assembly to an image side of the interactive lens assembly in turn. The first lens is of a negative focal power, an image side surface of the first lens is concave; the second lens is of a focal power; the third lens is of a positive focal power, an image side surface of the third lens is convex, and each of the first lens, the second lens and the third lens is made of a plastic material; the interactive lens assembly meets the following formulas: (CT1+CT2)/CT3<0.9; and ImgH/(f*TTL)?0.4 mm?1.

Abstract: Provided is an optical system, including, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, which is configured to move during focusing, and a third lens unit having a positive or negative refractive power, the first lens unit consisting of, in order from the object side to the image side, a positive lens (Gp1), a positive lens (Gp2), and a subunit including a plurality of lenses, the subunit including at least one negative lens, in which an Abbe number ?dGp1 of a material of the positive lens (Gp1), an Abbe number ?dGn1 of a material of a negative lens (Gn1) closest to the object side among the negative lenses of the subunit, and a partial dispersion ratio ?gFGn1 of the material of the negative lens (Gn1) are each appropriately set.

Abstract: A wide-angle lens comprises sequentially from an object side to an image side along an optical axis a first lens, a second lens, a stop and a third lens. The first lens is a biconcave lens and with negative refractive power. The second lens is a convex-concave lens with positive refractive power and includes a convex surface facing the object side and concave surface facing the image side. The third lens is with positive refractive power and includes a convex surface facing the image side. The wide-angle lens satisfies the following condition: 2.9<DL1DL2<3.1 wherein DL1 is an effective diameter of the first lens and DL2 is an effective diameter of the second lens.

Abstract: A compact optical system includes, in order from an object side to an image side, a first lens element, a second lens element and a third 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, wherein at least one of two surfaces of the second lens element is aspheric, and the second lens element is made of plastic material. The third lens element has positive refractive power, wherein at least one of two surfaces of the third lens element is aspheric, and the third lens element is made of plastic material. The compact optical system further comprises a stop located between the first lens element and the second lens element. The first, second, and third lens elements are all stationary relative to one another in a paraxial region.