Abstract: An imaging lens includes a front group having negative power, an aperture stop, and a rear group having positive power, in order from an object side. In the front group, a first lens surface has a convex shape toward the object side. In the rear group, a second lens surface has a convex shape toward the object side, a third lens surface has a convex shape toward the image side, and the third lens surface has an infrared ray cut coat. A curvature radius of the second lens surface is represented by Rr, a curvature radius of the third lens surface is represented by Re, a distance from the second lens surface to the third lens surface on an optical axis is represented by Da, and the following condition is satisfied: 1.6<(Rr+|Re|)/Da<2.3.

Abstract: An optical system internally has an intermediate imaging position that is conjugated to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, respectively. The optical system includes a magnification optical system having a first lens element and a second lens element positioned on the magnification side with respect to the intermediate imaging position; and a relay optical system having a plurality of lens elements, positioned on the reduction side with respect to the intermediate imaging position. The first lens element and the second lens element are positioned in this order from the magnification side, and the second lens element has a positive power. The optical system satisfies: 23<|f2/fw|<1000, wherein f2 is a focal length of the second lens element, and fw is a focal length of an entirety of the optical system at a wide-angle end.

Abstract: The imaging lens consists of, in order from the object side, a front group that includes a stop and has a positive refractive power, and a rear group. During focusing, the entire front group integrally moves, and the rear group remains stationary with respect to an image plane. The rear group includes one or more air lenses formed by two concave lens surfaces facing toward each other. The imaging lens satisfies Conditional Expressions: 0.1<Bf/f<0.9 and ?0.7<(Rrf+Rrr)/(Rrf?Rrr)<?0.025, where a back focal length of a whole system is Bf, a focal length of the whole system is f, and a curvature radius of an object side surface of the air lens in the rear group is Rrf and a curvature radius of an image side surface of the air lens in the rear group is Rrr.

Abstract: An optical imaging system includes a first lens group and a second lens group. The first lens group includes a first lens and a second lens. The second lens group includes a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The first to seventh lenses are sequentially disposed from an object side toward an imaging plane. The optical imaging system satisfies TTL/2Y<1.3, where TTL is a distance from an object-side surface of the first lens to the imaging plane, and 2Y is a diagonal length of the imaging plane.

Abstract: The present disclosure relates to optical lenses and discloses an imaging optical lens The imaging optical lens includes from an object side to an image side in sequence: 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 having a negative refractive power, a fifth lens having a positive refractive power, and a sixth lens having a negative refractive power. A focal length of the first lens is f1, a focal length of the second lens is f2, a curvature radius of an object-side surface of the third lens is R5, a curvature radius of an image-side surface of the third lens is R6, and the following relational expressions are satisfied: 20?(R5+R6)/(R5?R6)?100; and ?10?f2/f1??2.7.

Abstract: An imaging optical system includes a first lens having a concave image side surface and a negative refractive power; a second lens having a convex object side surface and a positive refractive index; a third lens having a concave object side surface and a negative refractive power; a fourth lens having a convex image side surface and a positive refractive power; and a fifth lens having a convex object side surface and a positive refractive power in the order from the object side to the image side, optionally includes a lens on the image side of the fifth lens. The imaging optical system satisfies conditional expressions [1] 1.94<n2<2.20 and [2] 15.0<?2<20.0, where ?2 and n2 represents an Abbe number and a refractive index of a lens material of the second lens L2 at d-line, respectively.

Abstract: An imaging lens includes a first lens having a negative refracting power and having a meniscus shape; a second lens having a negative refracting power and having a meniscus shape; a third lens having a positive refracting power and having a meniscus shape; an aperture stop; a fourth lens having a positive refracting power and having a bi-convex shape; a fifth lens having a negative refracting power and having a bi-concave shape; and a sixth lens having a positive refracting power and having a bi-convex shape The imaging lens has a total angle of view of 150 degrees or more, and fulfills predetermined conditional expressions.

Abstract: An imaging lens includes a first lens group having positive refractive power and a second lens group, arranged in this order from an object side to an image plane side. The first lens group includes a first lens, a second lens, and a third lens. The second lens group includes a fourth lens having positive refractive power, a fifth lens, and a sixth lens. The third lens has a concave surface facing the image plane side near an optical axis thereof. The fifth lens has a concave surface facing the image plane side near an optical axis thereof. The sixth lens has a concave surface facing the object side near an optical axis thereof. The second lens has a specific Abbe's number.

Abstract: The present invention discloses a lens device suitable for the large-diameter lenses (with diameter ?100 mm) of a vertical setup, and its adjustment method. The aberration caused by the self-gravity of lenses and the deformation generated by the clamping stress of the fixing device is compensated.

Abstract: The present invention provides a wide-angle camera lens consisting of seven lens elements. The wide-angle camera lens successively includes: a first optical lens with negative refractive power; a second optical lens with negative refractive power; a third optical lens with negative refractive power, an image side surface of the third optical lens being a convex surface; a fourth optical lens with refractive power; a fifth optical lens with refractive power; a sixth optical lens with refractive power; and a seventh optical lens with refractive power from an object side to an image side, wherein ?5.5<f1/f<?2; ?2.5<f5/f6<?0.5; f1 is an effective focal length of the first optical lens, f is an effective focal length of the wide-angle camera lens, f5 is an effective focal length of the fifth optical lens, and f6 is an effective focal length of the sixth optical lens.

Abstract: The present disclosure discloses a camera optical lens. The camera optical lens including, in an order from an object side to an image side, a first lens, a second lens having a positive refractive power, a third lens having a negative refractive power, a fourth lens, a fifth lens, and a sixth lens. The first lens is made of glass material, the second lens is made of plastic material, the third lens is made of plastic material, the fourth lens is made of plastic material, the fifth lens is made of glass material, and the sixth lens is made of plastic material. The camera optical lens further satisfies specific conditions.

Abstract: An imaging lens consists of, in order from the object side, a first lens group fixed during focusing, and a positive second lens group moved toward the object side during focusing from a distant object to a close object. The second lens group consists of, in order from the object side, a first cemented lens consisting of a biconvex lens and a negative lens having a smaller absolute value of curvature radius of the object-side surface than that of the image-side surface, and a second cemented lens as a whole having a positive refractive power and consisting of a negative lens having a smaller absolute value of curvature radius of the image-side surface than that of the object-side surface and a positive lens having a smaller absolute value of curvature radius of the object-side surface than that of the image-side surface. The imaging lens satisfies specific condition expressions.

Abstract: Provided are an imaging lens and an Imaging apparatus which includes this imaging lens. The imaging lens consists of, in order from an object side: a front group GF; a diaphragm St; and a rear group GR. The front group GF consists of, in order from the object side: a first lens L1 that is convex toward the object side and has a negative refractive power; a second lens L2 that has a negative refractive power; and a third lens L3 that has a positive refractive power. The rear group GR consists of, in order from the object side: a fourth lens L4 that has a positive refractive power; a fifth lens L5 that has a positive refractive power; a sixth lens L6 that has a negative refractive power; a seventh lens L7 that has a positive refractive power; and an eighth lens L8 that has a negative refractive power.

Abstract: A wide angle lens includes, in order from an object side to an image side along an optical axis, a negative first lens, a negative second lens, a positive third lens, a positive fourth lens, a negative fifth lens, and a positive sixth lens, wherein the sixth lens is adhered to the fifth lens to form a doublet lens. In addition, the wide angle lens further satisfies the condition of SD2/R2>0.6, where SD2 is half of an effective aperture of a surface of the first lens which faces the image side, and R2 is a radius of curvature of the surface of the first lens which faces the image side. Whereby, the FOV of the wide angle lens can be greater than 140 degrees, and the wide angle lens is compatible with a large-sized, e.g., 1/2.3?, photosensitive component.

Abstract: An imaging lens is constituted by, in order from the object side to the image side: a negative front group; a stop; and a positive rear group. The front group is constituted by, in order from the object side to the image side, a front group negative lens group, constituted by at least two negative lenses, and a front group positive lens group including one negative lens and one positive lens, in which a positive lens is provided most toward the object side. The rear group includes one negative lens and one positive lens. Conditional Formula (1) below is satisfied: Nan+0.01·?an<2.15??(1) wherein Nan and ?an respectively are the refractive index with respect to the d line and the Abbe's number with respect to the d line of the negative lens provided most toward the image side within the front group positive lens group.

Abstract: Provided is an optical system having, in order from an object, a positive first lens group (G1), an aperture stop (S) and a second lens group (G2), wherein the first lens group (G1) includes, in order from the object, a negative lens component (L1), a positive lens component (L2) and a first lens component (L3, L4), the image side surface of which is a concave surface facing the aperture stop (S), the second lens group (G2) includes, in order from the object, a second lens component (L5, L6), the object side surface of which is a concave surface facing the aperture stop (S), and a positive lens component (L8) disposed closest to the image, the first lens component (L1) and the second lens component (L2) face each other sandwiching the aperture stop (S), and the following conditional expressions (1) and (2) are satisfied: 1.5<fG1/f<2.6 . . . (1) and 2.1<TL/f<3.1 . . .

Abstract: An imaging lens includes an object-side lens group having positive refractive power; an aperture stop; and an image plane-side lens group having positive refractive power, arranged in this order from an object side to an image plane side. The object-side lens group includes a first lens having positive refractive power; a second lens having negative refractive power; and a third lens having positive refractive power. The image plane-side lens group includes a fourth lens having positive refractive power; and a fifth lens having negative refractive power. The first lens has an aspheric shape to have negative refractive power increasing toward a lens periphery from an optical axis, and has a surface on the object side having a positive curvature radius. The first to third lenses have specific focal lengths to satisfy specific conditions. The first to fifth lenses have specific Abbe's numbers to satisfy specific conditions.

Abstract: An optical module comprises: a first positive meniscus lens having a focal length F1 and comprising a first convex optical surface facing an object side, and a second concave optical surface facing an image side; a second positive meniscus lens having a focal length F2 and comprising a third concave optical surface facing the object side, and a fourth convex optical surface facing the image side. The four surfaces follow the curvature equation: Zi=CURViYi2/(1+(1?(1+Ki)CURVi2Yi2)1/2)+(Ai)Yi2+(Bi)Yi4+(Ci)Yi6+(Di)Yi8 with Mi=1?(1+Ki)(CURVi)2(Ri)2 where: i is the surface number, Ki is the conic constant of the i-th surface; CURVi is the curvature of the i-th surface at the optical axis; Ai, Bi, Ci, Di, are aspheric coefficients of the i-th surface; Ri is the effective radius of aperture of the i-th surface. The following relations are satisfied: 0.60<F1/F2<1.45, 2<sqrt(M2/M1)<7.

Abstract: An imaging lens including, in order from an object side: a first lens group G1 having positive refractive power; and a second lens group G2 having positive refractive power, a position of the first lens group G1 being fixed with respect to an image plane, the second lens group G2 consisting of a plurality of lens components, and given conditional expression being satisfied, thereby providing a compact imaging lens imaging lens having a large aperture and a wide angle of view and excellent optical performance over entire image frame with excellently correcting various aberrations upon focusing on an infinity object to a close object.

Abstract: An imaging optical system including, from the object side to the image side, a first lens group having positive refracting power, an aperture stop, and a second lens group having positive power, in which the first lens group consists of three lens subgroups, having positive, negative and positive refracting powers, respectively, from the object side to the image side, with satisfaction of the following: 4<(LTL+fB)/fB<15??(1) 0.3<D12/IH<4??(2) where fB is an on-axis distance, from an image side-surface in the second lens group to an image plane upon focusing at infinity, LTL is an on-axis distance from an object side-surface in the first lens group to the image side-surface in the second lens group, D12 is an on-axis length from an image side-surface in the first lens group to an object side-surface in the second lens group upon focusing at infinity, and IH is a maximum image height.

Abstract: An optical system includes, in order from an object side to an image side, a first lens unit of a positive refractive power, an aperture diaphragm, and a second lens unit of a positive refractive power. The first lens unit includes, in order from the object side to the image side, a cemented lens Lp1 made by joining a first lens of a positive refractive power and a second lens of a negative refractive power with each other, and a third lens of a positive refractive power which has a meniscus shape. The predetermined conditions are satisfied.

Abstract: An imaging lens satisfies the following conditional expression (1) and is configured by disposing a first lens group that has a positive refractive power, an aperture stop, and a second lens group that has a positive refractive power in order from an object side to an image side. The first and second lens groups are moved from the image side to the object side in a state in which a gap between the lens groups is constant on an optical axis when a subject distance changes from infinity to approach, and the second lens group is configured by at least two negative lenses and at least three positive lenses. 0.01<f2/f1<0.23??(1) where, f1: focal length of the first lens group when focused on an object at infinity f2: focal length of the second lens group when focused on an object at infinity.

Abstract: There is provided An imaging lens including a first lens group having a positive refractive power, an aperture stop, and a second lens group having a positive refractive power that are configured to be arranged sequentially from an object side to an image side. Focus is achieved by fixing the first lens group in an optical axis direction and moving the second lens group from the image side to the object side when a subject distance is changed from infinity to proximity. The first lens group includes an object-side lens group having a negative refractive power and an image-side lens group having a positive refractive power that are configured to be arranged sequentially from the object side to the image side. In an air space of the first lens group, an air space between the object-side lens group and the image-side lens group is set to be maximum.

Abstract: A lens system comprising, in order from an object side: a first lens group G1; and a second lens group G2 having positive refractive power; the first lens group G1 including a sub-lens group GS11 having positive refractive power, and a sub-lens group GS12 having negative refractive power, the sub-lens group GS12 having negative refractive power including a meniscus lens having a convex surface facing the object side, given conditions being satisfied, thereby providing a lens system having high optical performance with excellently correcting various aberrations, and an optical apparatus equipped therewith.

Abstract: A first lens group having positive refractive power and a second lens group are arranged in this order from an object side, and only the first lens group moves in the optical axis direction while focusing. The first lens group substantially consists of a positive 1-1 lens, a positive 1-2 lens, a positive 1-3 lens, a negative 1-4 lens, an aperture stop, a negative 1-5 lens, a positive 1-6 lens, and a positive 1-7 lens. The 1-3 lens and the 1-4 lens are cemented to each other, and the 1-5 lens and the 1-6 lens are cemented to each other. The second lens group substantially consists of a negative 2-1 lens and a positive 2-2 lens. Only the first lens group moves in the optical axis direction while focusing.

Abstract: An optical module (10) comprises a positive meniscus lens (16) having a focal length F1 and comprising a first convex optical surface (12) and a second concave optical surface (20), and a plano-convex lens (22) having a focal length F1 and comprising a third flat optical surface (24) and a fourth convex optical surface (26) from an object side (12) to an image side (14). The curvatures of the four optical surfaces (12, 20, 24, 26) are defined by the equation: Zi=CURViYi2/(1+(1+Ki)CURVi2Yi2)½)+(Ai)Yi2+(Bi)Yi4+(Ci)Yi6+(Di)Yi8, and the two lenses are defined by 0.35<F1/F2<0.90, 0.30<Conv2/Conv<0.70, and 0.50<M1/M2<1.

Abstract: An image forming lens consists of from an object side to an image side in the following order: a first group with a positive refractive power; an aperture stop; and a second group with a positive refractive power, wherein the second group includes, from the object side to the image side in the following order, a biconvex lens, a biconcave lens, a negative meniscus lens a convex surface of which faces the image side, a biconvex lens, and a positive meniscus lens a convex surface of which faces the image side.

Abstract: Provided is an endoscope objective optical system that is constituted of, in order from the object side, a positive first group, an aperture stop, and a positive second group, wherein the first group is constituted of a negative first lens whose surface on the object side is flat and a positive second lens; the second group is constituted of a combined lens formed of a positive third lens and a negative fourth lens; and Conditional Expressions (1) to (3) are satisfied. F31, F32, and f are the focal lengths of the third lens, the fourth lens, and the entire system, respectively; and R3 and R4 are the radii of curvature at the object-side surface and the image-side surface of the second lens, respectively. 1.2<f31/f<1.55 . . . (1), ?2.8<f32/f<?1.98 . . . (2), and 0.38<|R4+R3|/|R4?R3|<0.77 . . . (3).

Abstract: An imaging lens system includes a first lens group having a positive refractive power and a second lens group having a positive refractive power, the first lens group and the second lens group are sequentially arranged from an object side to an image surface. The first lens group includes 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 and having a concave surface toward the image surface, which are sequentially arranged from the object side to the image surface. The second lens group includes a cemented lens of a fourth lens that has a concave surface toward the object side and is a negative lens and a fifth lens that is a positive lens, which are sequentially arranged from the object to the image surface.

Abstract: The disclosed internal focusing large-aperture medium telephoto lens has as lens groups a positive first lens group, a positive second lens group, and a third lens group, in that order from the object side. When focusing on nearby objects, the first lens group and the third lens group have a fixed position relative to the image surface, and the second lens group displaces toward the object side. The second lens group has only one negative lens, and, in order from the object side, has at least a positive lens, a negative lens, and a positive lens. The following expression is fulfilled: ?0.5<(R1+R2)(R1?R2)<?0.1 (wherein, R1: radius of curvature of the object side surface of the negative lens in the second lens group; R2: radius of curvature of the image side surface of the negative lens in the second lens group).

Abstract: There are provided an inner focus lens consisting of a first lens group, an aperture diaphragm, and a second lens group in order from an object side. The first lens group has a positive first lens element, a positive second lens element, and a negative third lens element, or has a positive first lens element, a positive second lens element, a positive third lens element, and a negative fourth lens element, in order from the object side. One lens element in the second lens group is moved with respect to an image surface in focusing. The second lens group has five or more lens elements, and has a configuration including a negative lens element, a positive lens element, and a positive lens element in order from the object side.

Abstract: An imaging lens satisfies the following conditional expression (1) and is configured by disposing a first lens group that has a positive refractive power, an aperture stop, and a second lens group that has a positive refractive power in order from an object side to an image side. The first and second lens groups are moved from the image side to the object side in a state in which a gap between the lens groups is constant on an optical axis when a subject distance changes from infinity to approach, and the second lens group is configured by at least two negative lenses and at least three positive lenses. 0.01<f2/f1<0.

Abstract: An imaging lens includes an optical system having in order from an object side to an image side a first lens group having a positive refractive power and a second lens having a positive refractive power to image an optical image of an object, the first lens group and the second lens group being displaced in an extending amount different from one another to be focused on an object of a finite distance, the first lens group including a negative meniscus lens having a convex surface on the object side, a lens having a weak refractive power, and a lens having a positive refractive power, and the second lens group including four lenses or less or five lenses or less having at least one pair of a cemented lens.

Abstract: There is provided An imaging lens including a first lens group having a positive refractive power, an aperture stop, and a second lens group having a positive refractive power that are configured to be arranged sequentially from an object side to an image side. Focus is achieved by fixing the first lens group in an optical axis direction and moving the second lens group from the image side to the object side when a subject distance is changed from infinity to proximity. The first lens group includes an object-side lens group having a negative refractive power and an image-side lens group having a positive refractive power that are configured to be arranged sequentially from the object side to the image side. In an air space of the first lens group, an air space between the object-side lens group and the image-side lens group is set to be maximum.

Abstract: Provided is an endoscope objective optical system that is constituted of, in order from the object side, a positive first group, an aperture stop, and a positive second group, wherein the first group is constituted of a negative first lens whose surface on the object side is flat and a positive second lens; the second group is constituted of a combined lens formed of a positive third lens and a negative fourth lens; and Conditional Expressions (1) to (3) are satisfied. f31, F32, and f are the focal lengths of the third lens, the fourth lens, and the entire system, respectively; and R3 and R4 are the radii of curvature at the object-side surface and the image-side surface of the second lens, respectively. 1.2 <f31/f<1.55??(1), ?2.8<f32/f<?1.98??(2), and 0.38<|R4+R3|/|R4?R3|<0.77??(3).

Abstract: A wide-angle optical system comprises a front lens group (11), and a rear lens group (12), with an aperture stop (13) interposed between. The front lens group (11) includes at least two negative lenses (111, 112) and at least one positive lens (113). At least one of the positive lenses included in the front lens group (11) has at least one aspherical surface. The front lens group (11) satisfies the conditional expression vdp<29 where vdp is the minimum value of the Abbe number of the positive lens(es) included in the front lens group (11).

Abstract: An image forming lens consists of from an object side to an image side in the following order: a first group with a positive refractive power; an aperture stop; and a second group with a positive refractive power, wherein the second group includes, from the object side to the image side in the following order, a biconvex lens, a biconcave lens, a negative meniscus lens a convex surface of which faces the image side, a biconvex lens, and a positive meniscus lens a convex surface of which faces the image side.

Abstract: A micro-lens module including a first lens, a second lens, and an aperture stop is provided. The first lens is disposed between an object side and an image side, wherein a first surface of the first lens facing the object side is an aspheric surface, and the curvature radius of the aspheric surface is R1. The second lens is disposed between the first lens and the image side, wherein a second surface of the second lens facing the image side is an aspheric surface, and the curvature radius of the aspheric surface is R2. The aperture stop is disposed between the first lens and the second lens, wherein the distance from the first surface to the aperture stop is d1, and the distance from the second surface to the aperture stop is d2. The micro-lens module satisfies 6>d2/d1>2.5 and ?2.5<R1/R2<1.5.

Abstract: An image-forming lens includes: from an object side to an image side in order, a first group with a positive refractive power which includes less than or equal to five lens elements of two negative lenses and equal to or more than two positive lenses and in which a first lens element on a most object side is a negative meniscus lens a convex surface of which faces the object side; an aperture; and a second group with a positive refractive power which includes less than or equal to five lens elements including at least one cemented lens of a positive lens and a negative lens; wherein each of the first group and the second group shifts independently to perform focusing to a limited object distance, and an interval between the first lens element and a second lens element close to a surface on the image side of the first lens element: d11-2 and an interval between the second lens element and a third lens element close to a surface on the image side of the second lens element: d12-3 satisfy Conditional Expression

Abstract: A lens system includes a first lens with positive refractive power and a second lens with positive refractive power, and an image plane. The first lens includes a first surface and a second surface from the object-side to the image-side of the lens system. The lens system satisfies the conditions: D/TTL>1.18; 1.5<F1/F<1.7; 0.15<R2/(F1)2<0.25; wherein, D is a diameter of an effective imaging range of the image plane; TTL is a total length of the lens system, R2 is a radius of curvature of the second surface, F1 is a focal length of the first lens; F is a focal length of the lens system.

Abstract: An optical module comprises: a first positive meniscus lens having a focal length F1 and comprising a first convex optical surface facing an object side, and a second concave optical surface facing an image side; a second positive meniscus lens having a focal length F2 and comprising a third concave optical surface facing the object side, and a fourth convex optical surface facing the image side. The four surfaces follow the curvature equation: Zi=CURViYi2/(1+(1?(1+Ki)CURVi2Yi2)1/2)+(Ai)Yi2+(Bi)Yi4+(Ci)Yi6+(Di)Yi8 with Mi=1?(1+Ki)(CURVi)2(Ri)2 where: i is the surface number, Ki is the conic constant of the i-th surface; CURVi is the curvature of the i-th surface at the optical axis; Ai, Bi, Ci, Di, are aspheric coefficients of the i-th surface; Ri is the effective radius of aperture of the i-th surface. The following relations are satisfied: 0.60<F1/F2<1.45, 2<sqrt(M2/M1)<7.

Abstract: An image pickup lens includes a first lens having a positive meniscus shape convex toward an object side, a second lens disposed on an image side of the first lens and has a meniscus shape convex toward the image side, and an aperture stop disposed on the object side of the image side surface of the first lens, and satisfies conditional expressions given below, in which f is a focal length of the entire system, R2 is a paraxial radius of curvature of the object side of the first lens, R3 is a paraxial radius of curvature of the image surface of the first lens, and DD is a distance on the optical axis between the first and second lenses: 0.45<R2/R3<0.66; and 0.05<DD/f?0.117.

Abstract: A high performance fixed focal length optical imaging system for example for a cine camera is operable to receive radiation from an object space and deliver the received radiation through the optical system so as to form an image at an image surface in an image space. The imaging system has the advantage of providing high relative illumination and high contrast at elevated spatial frequencies even when using a fast aperture.

Abstract: An image capturing lens is disclosed, which is compact and capable of capturing an image at a wide angle though realizing low cost performance by enabling mass productions of wafer-scale lenses, and an image capturing device is disclosed, which uses this image capturing lens. For the purpose of attaining short focusing, a wide angle of view can be ensured by optimally disposing the power of a first lens block and the power of a second lens block so that a value of a conditional formula (1) becomes higher than a lower limit. Hereat, a wider angle can be attained by strengthening the positive power of the second lens block against the first lens block without increasing the overall length. While on the other hand, the value of the conditional formula (1) becomes lower than an upper limit, whereby the power of the second lens block is prevented from being excessively strengthened, the lens units of the second lens block can be configured with a small sag quantity, and moldability can be kept preferable, 0.

Abstract: Disclosed herein is a scanner apparatus. The scanner apparatus includes a light source, a reflecting means and an imaging means. The light source is located under an object, and radiates light so that the light is reflected from the object. The reflecting means is placed under the light source at a specific angle of inclination with respect to a surface of the object, and folds the path of the light when the light radiated by the light source is reflected from the object. The imaging means is placed along the path of the light reflected from the reflecting means, and condenses light reflected from the reflecting means and then acquires an image of the object.

Abstract: An optical system includes, in order from an object side to an image side, a first lens unit having a positive refractive power, an aperture stop, and a rear lens group. In the optical system, the rear lens group includes a second lens unit configured to move during focusing. The first lens unit includes n positive lenses (n is an integer greater than 1) and one or more negative lenses. With an order of an optical member counted from the object side towards the image side being indicated by i (i is an integer equal to or greater than 1), a refractive index and an Abbe number of a material of an i-th positive lens of the first lens unit with respect to d-line light (Ndi, ?di), maximum and minimum values of the Abbe number ?di (max(?di), min(?di)), a minimum value of the refractive index Ndi (min(Ndi)), a focal length of the first lens unit (fp), and a focal length of the entire optical system (f) are appropriately set.

Abstract: A wide-angle lens LN consists of, in order from an object side: a first lens group Gr1 having positive refractive power; and a second lens group Gr2 having positive refractive power; the second lens group Gr2 is movable toward the object side with fixing the first lens group Gr1, thereby carrying out focusing on a close object, and a given conditional expression is satisfied. Therefore, a wide-angle lens having high optical performance with suppressing variation in aberrations upon focusing in spite of being a large aperture, an imaging optical apparatus equipped therewith, and a digital equipment are provided.

Abstract: A photographing optical lens assembly includes, in order from an object side to an image side, a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface, and a second lens element with positive refractive power having a concave object-side surface and a convex image-side surface. At least one surface of the first lens element is aspheric and two surfaces of the second lens element are aspheric. The photographing optical lens assembly can also include a stop and an image plane. By adjusting the thicknesses of the first lens element and the second lens element as well as the allocation of the stop in the photographing optical lens assembly can effectively reduce the size as well as the sensitivity of the photographing optical lens assembly while gaining superior resolution.

Abstract: An imaging lens includes a first lens group having a positive refractive power, an aperture stop, and a second lens group having a positive refractive power, which are disposed in order from an object. The first lens group has a first lens component having a negative refractive power and a second lens component having a positive refractive power, which are disposed in order from the object, and conditions expressed by the expressions 0.12<f/f1<0.47 and 0.016<D12/f<0.079 are satisfied, when f1 is a focal length of the first lens group, f is a focal length of the imaging lens, and D12 is an air distance between the first lens component and the second lens component of the first lens group.

Abstract: A lens system includes a first lens with positive refractive power and a second lens with positive refractive power, and an image plane. The first lens includes a first surface and a second surface from the object-side to the image-side of the lens system. The lens system satisfies the conditions: D/TTL>1.18; 1.5<F1/F<1.7; 0.15<R2/(F1)2<0.25; wherein, D is a diameter of an effective imaging range of the image plane; TTL is a total length of the lens system, R2 is a radius of curvature of the second surface, F1 is a focal length of the first lens; F is a focal length of the lens system.