Abstract: An optical system consists of, in order from an object side to an image side, a front unit, an aperture stop, and a rear unit having positive refractive power as a whole. The rear unit includes a final lens disposed closest to the image side and having positive refractive power. A number of inequalities relating to the spatial relationship between the lenses and their refractive powers are satisfied.

Abstract: An imaging lens system, from an object side to an imaging plane, sequentially includes: a flat glass; a first lens with a negative focal power, a convex object side surface and a concave image side surface; a second lens with a positive focal power, a convex object side surface and a concave image side surface; a stop; a third lens with a positive focal power and a convex image side surface. The imaging lens system meets expressions: f/EPD?1.64; 0<BFL/IH<0.2; where f represents an effective focal length of the imaging lens system, and EPD represents an entrance pupil diameter of the imaging lens system; BFL represents a distance from a vertex of the image side surface of the third lens to the imaging plane on the optical axis, and IH represents the maximum image height of the imaging lens system.

Abstract: An optical imaging lens assembly includes, sequentially along an optical axis from an object side to an image side: a first lens, having a negative refractive power, an image-side surface of the first lens being a concave surface; a second lens, having a positive refractive power, an object-side surface of the second lens being a convex surface; and a third lens, having a refractive power, an object-side surface of the third lens being a convex surface. A Half of a diagonal length ImgH of an effective pixel area on an image plane of the optical imaging lens assembly, an effective focal length f of the optical imaging lens assembly and an entrance pupil diameter EPD of the optical imaging lens assembly satisfy: 3 mm<ImgH×f/EPD<4 mm. A maximal field-of-view FOV of the optical imaging lens assembly and the effective focal length f of the optical imaging lens assembly satisfy: 1 mm<tan(FOV/2)×f<2 mm.

Abstract: A first lens unit and a third lens unit are constituted by a lens which is rotationally symmetrical with respect to an optical axis and are disposed on the same optical axis, a first freeform-curved surface lens and a second freeform-curved surface lens have the same shape and are disposed to be rotated at 180 degrees with respect to the optical axis. Further, a refractive power of a second lens unit is variable due to the first freeform-curved surface lens and the second freeform-curved surface lens moving in opposite directions. The first freeform-curved surface lens and the second freeform-curved surface lens are moved in the Y-axis direction in association with movement of some of lens groups constituting the first lens unit and the third lens unit when positional states of the lenses are changed from a wide-angle end state to a telephoto end state.

Abstract: An imaging optical system according to the present disclosure includes a first lens, a second lens, and a third lens. The first lens includes an image-plane-side lens surface having an aspherical shape with an inflection point. The second lens has a meniscus shape including a concave surface toward object side. The third lens has a meniscus shape including a concave surface toward image plane side. The first lens, the second lens, and the third lens are disposed in order from the object side toward the image plane side. The imaging optical system is provided as a bi-telecentric optical system.

Abstract: Disclosed is a small lens system including a first lens, a second lens, and a third lens sequentially arranged from an object along an optical axis, wherein the thickness (ct1) of the first lens, the thickness (ct3) of the second lens, and the thickness (ct5) of the third lens satisfy ct1/ct3>1.5 and ct1/(ct3+ct5)>0.8, the refractive power (P2) of the second lens satisfies ?0.01<P2<0.01, the lens thickness (et) at a predetermined height and the center thickness (ct) of the second lens thereof satisfy |et?ct|<5 ?m up to 30% of the height of the rear effective diameter thereof and satisfy et?ct<?20 ?m at 70% of the height of the rear effective diameter thereof, and the f-number of the lens system is less than 1.7.

Abstract: An optical filter system and a video endoscope therefor are disclosed. The optical filter system is arranged in a distal end section of a shaft. At least one image sensor for receiving image light is positioned in the distal end section. The optical filter system contains an optical filter and an objective lens system with a three or more lenses to collect image light and to pass it to the image sensor. The filter has transmission characteristics that vary relative to the radial distance from its center and is located between the first lens and the second lens of the objective lens system. Used in conjunction with fluorescence imaging, emission radiation collected by the image sensor is substantially free of excitation radiation. Additionally, a display system clearly delineating the regions with reliable fluorescence and/or visible light is also disclosed.

Abstract: A folded optical arrangement for use in a view-through display to transmit an image from an image source to a user's eye, the arrangement providing a folded optical transmission path and comprising: an optical system having a first optical element comprising a first plurality of optically powered surfaces; and a second optical element comprising at least one optically powered surface, the optical system configured to receive light forming the image from an image source, and to present a virtual image of the image source to the user with an apparent focus between a predetermined distance and optical infinity; wherein the first plurality of optically powered surfaces and the at least one optically powered surface of the second optical element are arranged to define a plurality of interfaces along the folded optical path and wherein a refractive index change at each interface is predetermined to control the direction of light passing through the or each interface; and wherein one surface of the first optical ele

Abstract: A lens system (1) for a video endoscope comprises, in order from an object side, a cover glass (20), a first lens (40), a second lens (60) and one or more further lenses, wherein all lenses are single lenses. An aperture stop (21) is arranged at the object side of the first or the second lens (40, 60), all lenses on an image side of the aperture stop (21) are aspherical, all lenses are made of glass or of a crystalline material, and at least one lens has a refractive index n approximately equal to or exceeding 1.66. The invention also relates to an endoscope objective, to a video endoscope, and to a method for assembling an endoscope objective.

Abstract: A camera lens is provided, including, in order from an object side to an image side along an optical axis: a first lens having a positive refractive power; a second lens; and a third lens. An equivalent length TL of an actual propagation distance of a principal ray from an object side surface of the first lens to an imaging plane in the air and an entrance pupil diameter EPD of the camera lens satisfy: 3.5<TLEPD<4.0.

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

Abstract: A camera optical lens includes, from an object side to an image side, a first lens having a positive refractive power; a second lens having a negative refractive power; a third lens having a positive refractive power; a fourth lens; a fifth lens having a negative refractive power; a sixth lens; a seventh lens having a positive refractive power; and an eighth lens having a negative refractive power. The camera optical lens satisfies: 1.50?f7/f?4.00, 1.20?R6/R5?5.00 and 1.00?d10/d12?3.50, where f denotes a focal length of the camera optical lens, f7 denotes a focal length of the seventh lens, R5 denotes a curvature radius of an object-side surface of the third lens, and R6 denotes a curvature radius of an image-side surface of the third lens. The camera optical lens can achieve good optical performance while satisfying design requirements for ultra-thin, wide-angle lenses having large apertures.

Abstract: There is provided an optical-fiber connector endface inspection microscope system for inspecting an endface of an optical-fiber connector. It comprises one or more image detector for capturing at least one image of the endface to be inspected; an objective lens system comprising a focusing lens for adjusting a focus of the objective lens system on the image detector and a fixed relay lens; a main housing structure enclosing the image detector and the focusing lens; and at least one interchangeable optical head releasably connectable to the main housing structure and enclosing the fixed relay lens, wherein the optical head is releasably connectable to an adapter tip for interfacing with the optical-fiber connector to be inspected.

Abstract: An optical imaging system for pickup, sequentially arranged from an object side to an image side, comprising: the first lens element with positive refractive power having a convex object-side surface, the second lens element with refractive power, the third lens element with refractive power, the fourth lens element with refractive power, the fifth element with refractive power; the sixth lens element made of plastic, the sixth lens with refractive power having a concave image-side surface with both being aspheric, and the image-side surface having at least one inflection point.

Abstract: An imaging device having an imaging field of view, the imaging device including at least one illumination port configured to output light for illuminating a target; an imaging sensor to detect light traveling along an optical path to the imaging sensor; and a first movable window positioned upstream of the sensor with respect to a direction of travel of light along the optical path, wherein the first movable window is configured to move into the optical path in a deployed position for modifying light received from the target.

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: The disclosure provides an optical imaging lens assembly, which includes nine lenses. From an object side to an image side, the nine lenses are sequentially: a first lens with positive refractive power, a second lens with positive refractive power, of which an object-side surface thereof is a convex surface while an image-side surface is a concave surface, a third lens with refractive power, of which an object-side surface thereof is a convex surface while an image-side surface is a concave surface, a fourth lens with refractive power, a fifth lens with refractive power, a sixth lens with refractive power, a seventh lens with positive refractive power, an eighth lens with refractive power, and a ninth lens with negative refractive power. The nine lenses are independent of one another and have air spaces on an optical axis.

Abstract: The present disclosure discloses an optical lens assembly including, sequentially from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens. An object-side surface of the first lens is convex, and an image-side surface thereof is concave. The second lens has negative refractive power. The third lens has positive refractive power. The fourth lens has positive refractive power, and both an object-side surface and an image-side surface thereof are convex. The fifth lens has positive refractive power. The sixth lens has negative refractive power.

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 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: 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: 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: 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: 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: 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: 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.