Abstract: A high-performance lens system includes lens elements of small diameters for projecting enlarged images from light valves (mainly Digital Micromirror Devices (DMDs)) for forming images by changing reflecting directions of light. The lens system includes, sequentially in order from a magnifying side, a first lens group which makes up a substantially afocal optical system as a whole and a second lens group having a positive refractive power as a whole. Depending on the application a third lens group made up of a single positive lens element is provided in the vicinity of the light valve on a contracting side of the second lens group.

Abstract: An imaging lens unit comprising, in order from the object side, a first lens having a meniscus shape with its convex surface on the object side, an aperture stop and a second lens having a meniscus shape with its convex surface on the image side. A maximal value of a tangent angle within a range of a lens surface effective diameter of the surface on the object side of the first lens is 70 to 90 degrees. A maximal value of a tangent angle within a range of a lens surface effective diameter of the surface on the image side of the second lens is 70 to 90 degrees.

Abstract: A high-performance lens system includes lens elements of small diameters for projecting enlarged images from light valves (mainly Digital Micromirror Devices (DMDs)) for forming images by changing reflecting directions of light. The lens system includes, sequentially in order from a magnifying side, a first lens group which makes up a substantially afocal optical system as a whole and a second lens group having a positive refractive power as a whole. Depending on the application a third lens group made up of a single positive lens element is provided in the vicinity of the light valve on a contracting side of the second lens group.

Abstract: In an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the negative lens group is disposed at an image side of the of the aperture stop, the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1), and a line when an upper limit value is in a range of the following conditional expression (1), and an area determined by following conditional expressions (2) and (3). 1.45<??2.15??(1) 1.30<Nd<2.20??(2) 3<?d<12??(3) Here, Nd denotes a refractive index, and ?d denotes an Abbe's number.

Abstract: An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the negative lens group is disposed at an object side of the aperture stop, the negative lens group has a cemented lens which is formed by cementing a plurality of lenses, and in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and an area determined by following conditional expressions (2a) and (3a). 1.45<?<2.15??(1a) 1.30<Nd<2.

Abstract: An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the positive lens group is disposed at an image-plane side of the aperture stop, the positive lens group has a cemented lens which is formed by cementing a plurality of lenses, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1), and a line when an upper limit value is in a range of the following conditional expression (1), and in an area determined by following conditional expressions (2) and (3) 1.45<??2.15??(1) 1.30<Nd<2.

Abstract: Provided is an optical system in which chromatic aberrations can be excellently corrected in spite of environmental changes, to thereby maintain high optical performance. The optical system includes: a plurality of optical elements each having refractive surfaces located in a light incident side and a light exit side; and an aperture stop. A focal length, an Abbe number of a material, and an extraordinary partial dispersion ratio of each of an l-th optical element and an r-th optical element which satisfy a condition related to the extraordinary partial dispersion ratio are suitably set.

Abstract: Disclosed is an optical head apparatus comprising: a light source; a collimating means of converting a beam of light emitted from the light source into a substantially parallel beam of light; a focusing means of focusing the light onto an information medium surface; a beam splitting means of splitting the beam of light modulated by the information medium; and a light receiving means of receiving the light modulated by the information medium, wherein a lens having a negative power and a lens having a positive power are arranged in this order as viewed from the collimating means side between the collimating means and the focusing means, and at least either one of the lenses is moved along an optical axis to correct spherical aberration occurring on the information medium surface, and wherein the distance from the lens having the positive power to the focusing means is set substantially equal to the focal length of the lens having the positive power.

Abstract: An exemplary wide-angle lens system includes, in order from the object side to the image side thereof, a first lens element having a negative optical power and crescent-shaped convex to the object side and a second lens element having a positive optical power. The first and second lens elements are plastic, and the wide-angle lens system satisfies the conditions R1F/R1R>1.24, and R2F/R2R>3.28, where R1F is the radius of curvature of an object-side surface of the first lens element, R1R is the radius of curvature of an image-side surface of the first lens element, R2F is the radius of curvature of an object-side surface of the second lens element, and R2R is the radius of curvature of an image-side surface of the second lens element.

Abstract: The invention relates to an image pickup system comprising an electronic view finder suitable for achieving compactness and having a sufficient viewing angle of field and satisfactory optical performance. The image pickup system comprises an image pickup device, an image display device for displaying an image, a controller for converting image formation obtained from the image pickup device into a signal that enables the image information to be formed on the image display device, and a viewing optical system for guiding an image displayed on the display device to a viewers eye. The viewing optical system comprises at least three lenses.

Abstract: An image capture lens includes: when changed from infinity to close focusing, a first lens group moving from an image to an object with positive refractive power; and a second lens group fixed relatively to the image with negative refractive power, wherein the first lens group includes a negative first lens having a strong concave surface facing the image, the second lens group includes one negative lens having a strong concave surface facing the image or a negative cemented lens including positive and negative lenses, and conditional expressions; 0.7<f1/fi<0.9, 1.0<bf/fi<1.4, 0.5<Rf2/Rr2<1 are satisfied where fi: overall focal length, f1: first-lens-group focal length, bf: overall back focus, Rf2: radius of curvature of the image-side surface of the lens nearest to the object, and Rr2: radius of curvature of the surface nearest to the image of the second lens group.

Abstract: A fixed focal length lens system comprises a first lens unit and a second lens unit. The first lens unit comprises a plastic negative lens, wherein the first lens unit has a negative diopter, and the plastic negative lens comprises at least one non-spherical surface. The second lens unit comprises a plastic positive lens, wherein the second lens unit has a positive diopter. The fixed focal length lens system satisfies the equation: ?1<2Gf/1Gf<0, wherein 1Gf is the focal length of the first lens unit and 2Gf is the focal length of the second lens unit.

Abstract: The present invention belongs to a technical field related to a composite optical element including a first optical component and a second optical component coupled to the first optical component. In a composite optical element 1 including a first optical component 10 and a second optical component 20 coupled to the first optical component 10, shape accuracy of the second optical component 20 is improved to prevent reduction in optical performance. A ring member (106) is placed on a peripheral portion of a lens surface (10b) of the first optical component (10), the ring member (106) having a height hi from the lens surface (10b) substantially uniform in a circumferential direction of the first optical component (10).

Abstract: An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the positive lens group is disposed at an object side of the aperture stop, the positive lens group has a cemented lens which is formed by cementing a plurality of lenses, in a rectangular coordinate system in which a horizontal axis is let to be Nd and a vertical axis is let to be ?d, when a straight line indicated by Nd=?×?d+? (where, ?=?0.017) is set, Nd and ?d of at least one lens forming the cemented lens is included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1a), and a line when an upper limit value is in a range of the following conditional expression (1a), and of an area determined by following conditional expressions (2a) and (3a). 1.45<?<2.15??(1a) 1.30<Nd<2.

Abstract: A lens assembly includes, in order from an object side toward an image side along an optical axis thereof, a first lens having positive refractive power, and a second lens. The lens assembly satisfies the following conditions: 0<|f1/f|<2 and 0<|f2/f|<7, wherein f is an effective focal length of the lens assembly, f1 is an effective focal length of the first lens, and f2 is an effective focal length of the second lens. The first lens has at least one spherical surface, thus effectively decreasing the production cost of the lens assembly.

Abstract: An objective lens for endoscopes has a front lens unit and a rear lens unit with an aperture stop between them. The front lens unit includes a first lens element with negative refracting power of a meniscus shape, with a convex surface facing the object side and a second lens element with positive refracting power, and the rear lens unit includes a third lens element with positive refracting power, with a surface of the minor radius of curvature facing the image side and a cemented lens component of a fourth lens element with positive refracting power and a fifth lens element with negative refracting power. The objective lens satisfies the following conditions: ?2<SF<?0.9 0.94<D/(f×sin ?)<1.7 0.86<(D1+D2?f1)/(2×f3)<1.

Abstract: An optical system comprising two lens cells, each lens cell comprising multiple lens elements, to provide imaging over a very wide image distance and within a wide range of magnification by changing the distance between the two lens cells. An embodiment also provides scannable laser spectroscopic measurements within the field-of-view of the instrument.

Abstract: An optical system includes a first lens with a functional film having film hardness of equal to or less than H formed on at least on one surface thereof, and a second lens located opposite the surface with the functional film of the first lens and having a diameter larger than that of the surface with the functional film, wherein the first lens and the second lens are in marginal contact with each other.

Abstract: The invention relates to an image pickup system comprising an electronic view finder suitable for achieving compactness and having a sufficient viewing angle of field and satisfactory optical performance. The image pickup system comprises an image pickup device, an image display device for displaying an image, a controller for converting image formation obtained from the image pickup device into a signal that enables the image information to be formed on the image display device, and a viewing optical system for guiding an image displayed on the display device to a viewer's eye. The viewing optical system comprises at least three lenses.

Abstract: In the case where a lens unit where two ore more transparent resin lenses are combined is constituted, at least one transparent resin lens contains infrared absorbent. When the lens unit is assembled, an infrared laser is emitted to a joined portion between the transparent resin lens and the other transparent resin lens. As a result, the emitted infrared ray is absorbed by the infrared absorbent, so that the transparent resin lenses are welded to each other. An opaque lens barrel which holds the entire lens unit and the transparent resin lenses are joined by welding.

Abstract: An inverse telephoto with correction lenses comprises five lens elements with refractive power, from the object side to the image side: a first lens element with negative refractive power having a concave image-side surface; a second lens element with positive refractive power having a convex image-side surface; a third lens element with a convex object-side surface; a fourth lens element with a concave image-side surface; a fifth lens element with positive refractive power having a convex image-side surface, at least one of an object-side surface and the image-side surface of the fifth lens element being aspheric; and an aperture stop located between the first lens element and the second lens element. At least three of the surfaces of the first, second, third, fourth and fifth lens elements are aspheric.

Abstract: The present invention provides an optical analyzer having illumination optics that include a light source, such as a laser or other source, adapted to emit a collimated, or approximately collimated, light beam, a focusing lens that focuses the beam onto a focus spot within a detection region, and beam-adjusting optics positioned in the light path between the light beam source and the focusing lens, which allow for precise positioning of the focus spot within the detection region. The beam-adjusting optics of the present invention comprise at least one movable focusing lens, mounted in a positioning device that allows repositioning of the lens in a plane perpendicular to the light path.

Abstract: A fixed-focus lens including a first lens group and a second lens group is provided. The first lens group has a negative refractive power, and consists essentially of a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from an object side to an image side. Refractive powers of the first, second, third, and fourth lenses are negative, negative, positive, and negative respectively. The second lens group is disposed between the first lens group and the image side, and has a positive refractive power. The second lens group includes a fifth lens and a sixth lens arranged in sequence from the object side to the image side. Refractive powers of the fifth lens and the sixth lens are both positive.

Abstract: An endoscope objective lens is provided and has a front-group divergent lens system, an aperture stop, and a rear-group convergent lens system in this order from the object side. The back focal length Bf of the whole system is longer than 2.5 times the combined focal length f of the whole system. The rear-group convergent lens system includes a cemented lens. The endoscope objective lens satisfies the specific formula.

Abstract: An imaging system comprises a rolling-reset imager that forms an electronic image of an object, a light source illuminating the object with pulsed light, and a bandpass optical filter disposed between the object and the rolling-reset imager. The pulsed light has an illumination frequency spectrum and an illumination pulse width defining an effective exposure time for forming the image of the object. The bandpass optical filter has a frequency pass band permitting transmission of a significant portion of the illumination frequency spectrum while at least approximately inhibiting transmission of at least some light having frequencies outside the illumination frequency band.

Abstract: An exemplary projection lens includes, in this order from the magnification side to the minification side thereof, a negative lens group of negative fraction power, and a positive lens group of positive fraction power. The projection lens satisfies the formulas of: ?2.5<F1/F<?1.5; and 1.3<F2/F<1.5, where F1, F2, and F respectively represent the effective focal lengths of the negative lens group, the positive lens group, and the projection lens.

Abstract: An exemplary lens includes an active part configured for refracting light transmitting therethrough, an inactive part surrounding the active part, and a collar formed on a surface of the inactive part.

Abstract: Providing an optical system having excellent optical performance with sufficiently correcting spherical aberration and curvature of field, an imaging apparatus, and a method for forming an image by the optical system. The optical system includes a plurality of lens groups, at least one of the plurality of lens groups having an A lens that satisfies at least one of given conditional expressions.

Abstract: Large aperture optical systems that are extremely well corrected over a large flat field and over a large spectral range are disclosed. Breathing and aberration variation during focusing are optionally controlled by moving at least two groups of lens elements independently. Aberration correction in general is aided by allowing the working distance to become short relative to the format diagonal. Field curvature is largely corrected by a steeply curved concave surface relatively close to the image plane. This allows the main collective elements to be made of low-index anomalous dispersion materials in order to correct secondary spectrum. In wide-angle example embodiments, distortion may be controlled with an aspheric surface near the front of the lens.

Abstract: A wide-angle image pick-up lens system includes a first lens group with negative refracting power and a second lens group with positive refracting power. The first lens group and the second lens group are aligned in order from an object side to an image side. The first lens group and the second lens group satisfy the following conditions: ?0.15<f10/f12<?0.05, 0.3<f10/f14<0.8, wherein f10 is a focal length system, f12 is an effective focal length of the first lens group, and f14 is an effective focal length of the second lens group. The first lens group includes a third lens with positive refracting power. A refractive index of the third lens is above of 1.85.

Abstract: A super wide-angle imaging system has a short total track length. The lens system is a retrofocus type lens system that uses only a few lenses with no cemented lens elements. Acceptable performance is achieved by taking advantage of subsequent digital image processing. The compact lens system is designed to create optical images that can be restored by subsequent digital processing that compensates for otherwise unacceptable aberrations introduced by the lens system.

Abstract: A lens unit according to the present invention is capable of varying power for forming an image onto an image pickup element. The lens unit includes: a plurality of lens groups, a diaphragm, and a shutter. In the plurality of lens groups, a distance between a k-th lens group counting from an object side and a (k+1)-th lens group arranged at an image side of the k-th lens group changes for varying power. The diaphragm is arranged between a position at an image side of the k-th lens group and a lens surface facing the object side of a lens closest to the image in the (k+1)-th lens group. The shutter is provided with an aperture in a noncircular shape and fulfills the predetermined conditional formulas.

Abstract: An objective for use in a night sight device has a front lens group and a rear lens group. The lenses of the front lens group have essentially equal diameters, whereas the lenses of the rear lens group have increasingly large diameters starting from the front end of the lens group.

Abstract: An optical lens assembly comprises two plastic lenses with refractive power: from the object side to the image side: a first lens with positive refractive power, and a second lens with negative refractive power. A front surface and a rear surface of the first lens is convex and aspherical, a refractive index N1 of the first lens satisfies the relation: 1.6>N1>1.5, a focal length of the first lens is f1, and a focal length of optical system is f, and they satisfy the relation: f/f1>2.0. A front surface of the second lens is concave, a rear surface of the second lens is convex, and both the front and rear surfaces is aspherical, a refractive index N2 of the second lens satisfies the relation: N2>1.55. An aperture is located in front of the first lens for controlling the brightness of the optical system.

Abstract: To provide a compact and low-cost projector lens capable of appropriately performing temperature correction and obtaining excellent image quality although using a plurality of plastic lens elements, a first lens unit having negative refractive power and a second lens unit having positive refractive power are provided from the screen side, the first lens unit includes a negative meniscus lens element 1b being a plastic lens element, being convex to the screen side and having an aspherical surface, the second lens unit includes: a negative lens element 2b being a plastic lens element and having an aspherical surface; and at least two positive lens elements having anomalous dispersibility and a temperature coefficient of a negative refractive index, and an image plane fluctuation by a temperature change due to a temperature coefficient of a negative refractive index of the plastic lens elements 1b and 2b of the first and second lens units is corrected by the temperature coefficient of the predetermined negative

Abstract: A light shield sheet has an aperture that restricts a range of light transmission. In the light shield sheet, the thickness of the inner circumference in the periphery of the aperture is smaller than the thickness of the outer circumference.

Abstract: A subminiature imaging optical system includes a first lens including a first lens part having a convex object-side surface, a second lens part having an object-side surface in contact with an image-side surface of the first lens part, and a third lens part having an object-side surface in contact with an image-side surface of the second lens part and a concave image-side surface, about the optical axis; and a second lens including a fourth lens part having an object-side surface with a convex center and a concave peripheral portion about the optical axis, a fifth lens part having an object-side surface in contact with an image-side surface of the fourth lens part, and a sixth lens part having an object-side surface in contact with an image-side surface of the fifth lens part, and an image-side surface with a concave center and a convex peripheral portion about the optical axis.

Abstract: An imaging lens unit comprising, in order from the object side, a first lens having a meniscus shape with its convex surface on the object side, an aperture stop and a second lens having a meniscus shape with its convex surface on the image side. A maximal value of a tangent angle within a range of a lens surface effective diameter of the surface on the object side of the first lens is 70 to 90 degrees. A maximal value of a tangent angle within a range of a lens surface effective diameter of the surface on the image side of the second lens is 70 to 90 degrees.

Abstract: Aspects of the invention can provide an imaging device that can include a first optical element having a first focal length, and a second optical element having a variable second focal length. The second optical element can be located at a fixed first distance of approximately the first focal length away from the first optical element. Thus, such an imaging device can permit an optical system to focus on an object at various distances and at a constant magnification with no moving parts.

Abstract: A first lens group having a negative refractive power, an aperture diaphragm, and a second lens group having a positive refractive power are arranged in order from an enlargement side. A reduction side of a projection lens is made essentially telecentric. Further, cemented triplet lenses, each of which includes cemented three lenses, are provided in the first lens group and the second lens group, respectively. Further, air spacing which enables placement of a mirror is ensured between the first lens group and the second lens group. Moreover, specific conditional expressions for the lens are satisfied.

Abstract: An imaging lens assembly (30) for a camera assembly (20) of an imaging-based bar code reader (10) for focusing an image (100?) of a target object (100) within a field of view (FV) of the camera assembly (20) onto a sensor array (28) of the camera assembly (20). The imaging lens assembly includes a front aperture stop (31) facing the field of view (FV), the aperture stop (31) including an aperture (31a) through which light from the field of view (FV) passes. The imaging lens assembly (30) further including a three lens system (36) disposed rearward of the front aperture stop (31) and a meniscus lens (35) disposed rearward of the three lens system (36). The three lens system (36) and the meniscus lens (35) receiving light passing through the aperture (31a) and focusing the light onto the sensor array (28).

Abstract: An image pickup lens system includes, successively in order from an object side, an aperture stop, a first lens as a double-convex positive lens, and a second lens as a negative meniscus lens having a convex surface on an image side. Each of the first and second lenses has at least one aspherical surface. The image pickup lens system satisfies the following conditional formulas (1), (2), and (3): 0.24<|f1/f2|<0.68??(1) 0.83<R1/f<3.68??(2) 0.13<D3/f<0.31, where??(3) f1: the focal length of the first lens; f2: the focal length of the second lens; R1: the paraxial radius of curvature of the surface on the object side of the first lens; f: the focal length of the entire system; and D3: the axial surface-to-surface distance between the first lens and the second lens.

Abstract: The invention discloses a lens set adapted to a webcam. The webcam has a first focal length. The lens set according to the invention includes a first lens and a second lens. The first lens is used to refract a light to generate a refracted light substantially parallel to an optical axis of the first lens. The second lens is used to focus the refracted light and project it to the webcam. The combination of the lens set and the webcam has a second focal length smaller than the first focal length.

Abstract: A wide-angle lens system includes a negative front lens group and a positive rear lens group, in this order from the object. The negative front lens group includes a negative first sub-lens group and a positive second sub-lens group, in this order from the object. The positive rear lens group includes cemented lens elements having a positive lens element, a negative lens element and a positive lens element. The wide-angle lens system satisfies the following conditions: ?0.8<fla/flb<?0.2??(1) 0.7<f/fR<1.1??(2) wherein fla designates the focal length of the negative first sub-lens group; flb designates the focal length of the positive second sub-lens group; f designates the focal length of the entire wide-angle lens system; and fR designates the focal length of the positive rear lens group.

Abstract: An auto-focusing image-forming lens set, which includes a first optical system, a second optical system and an image forming face arranged in line along an optical axis. The first optical system has a predetermined number of convex lenses arranged along the optical axis, and defines with image forming face a fixed distance.

Abstract: A lens module includes a lens barrel, a first lens, a second lens, a plurality of electrostrictive members and a controlling unit. The first lens has a first optical axis thereof, the second lens has a second optical axis thereof, the first and second lenses being received in the lens barrel. The electrostrictive members are arranged in the lens barrel and connected with the second lens. The controlling unit is configured for controlling the electrostrictive members so as to adjust the second optical axis of the second lens to be in alignment with the first optical axis of the first lens. A camera module using the lens module is also provided.

Abstract: An imaging lens includes: in order from an object side, an aperture diaphragm; a first lens of a positive lens having a convex surface on the object side; a second lens of a meniscus lens having a concave surface on the object side; and a third lens. The imaging lens satisfies: f/f3<0.95 and BR2<0. BR2 satisfies BR2=A/D4, A represents a distance from a vertex position on a object-side surface of the second lens and on an optical axis to a position on a image-side surface of the second lens through which a light ray passes toward a corner of an image height, provided that a traveling direction of the light ray is taken as appositive direction, and D4 represents a center thickness of the second lens. f represents a focal length of the imaging lens. f3 represents a focal length of the third lens.

Abstract: An image forming optical system comprising, in order from an object side: a negative lens unit having one or two negative lenses without including any positive lens; a reflecting member; an aperture stop; and a positive lens unit having one or two positive lenses without including any negative lens.

Abstract: A high-performance lens system including lens elements of small diameters for projecting on to a screen or the like in an enlarged fashion images from light valves such as mainly DMDs (Digital Micromirror Devices) for forming images by changing reflecting directions of light. A lens system is provided which includes, sequentially in that order from a magnifying side, a first lens group which makes up a substantially a focal optical system as a whole and a second lens group having a positive refractive power as a whole, and depending upon applications, a third lens group made up of a single positive lens element is provided in the vicinity of a light valve such as a DMD on a contracting side of the second lens group.

Abstract: A zoom lens includes, in sequence from the object side: a first lens group with an overall negative refractive power; and a second lens group with an overall positive refractive power. A zoom factor changes by moving the second lens group. Focal adjustments are made by moving the first lens group accompanied by the change of the zoom factor made by the movement of the second lens group. The first lens group includes a first lens having a negative refractive power and a second lens having a positive refractive power. The second lens group includes a third lens having a positive refractive power, a fourth lens with a positive refractive power and a fifth lens with a negative refractive power bonded together, and a sixth lens with a positive refractive power. The bonded lenses form a meniscus shape with a convex surface facing the object side. The resulting lens is short in length, compact, thin, and suitable for digital still cameras.