Abstract: Head-up display includes: display element for displaying an image, and a projection optical system for projecting the image, which is displayed on display element, onto viewing region of viewer. The projection optical system includes combiner that is disposed at a position in an optical path from display element to viewing region of viewer. Combiner has a surface at which light incident from display element enters; the surface has a curved surface shape. Combiner has an effective region corresponding to viewing region of viewer. In the effective region, combiner has a horizontal cross-sectional shape that changes in thickness along from the center toward an end.

Abstract: A fixed focal length lens system includes, in order from an object side to an image side, first lens element having negative power, second lens element having negative power, third lens element having positive power, fourth lens element having power, fifth lens element having power, and sixth lens element having positive power. The third lens element is a positive meniscus lens element having a convex surface on the image side. At least one of second to sixth lens elements is made of glass. The fixed focal length lens system satisfies condition (1) below: 0<(L1R2+L2R1)/(L1R2?L2R1)<100??(1) where L1R2 is a radius of curvature of an image-side surface of first lens element, and L2R1 is a radius of curvature of an object-side surface of second lens element.

Abstract: A fixed-focus lens system includes, in order from an object side to an image side, a first lens element having negative power, the first lens element having a convex surface opposite to an object, a second lens element having positive power, the second lens element having a concave surface opposite to the object, a third lens element having positive power, a fourth lens element having negative power, and a fifth lens element having positive power. A half angle of view of the fixed-focus lens system is 50 degrees or more, and a shape of the convex surface on the object side of the first lens element has at least one inflection point at a part except for the optical axis. With this configuration, a fixed-focus lens system capable of favorably correcting various aberrations can be provided.

Abstract: A single-focal lens system includes a first lens group having positive power, an aperture diaphragm, and a second lens group having positive power, in this order from an object side to an image side. The first lens group includes a first lens element having negative power, a second lens element having negative power, and a third lens element having positive power in this order from the object side to the image side. The second lens group includes a fourth lens element having power and a fifth lens element having positive power. When fG1 is a focal length of the first lens group at a d-line, fG2 is a focal length of the second lens group at the d-line, f4 is a focal length of the fourth lens element at the d-line, f is a focal length of an entire system at the d-line, and w is a half angle of view, a condition (1), a condition (3c) and a condition (6) shown below are satisfied. 0.5<fG1/fG2<3.0??(1) 11.

Abstract: Head-up display includes: display element for displaying an image, and a projection optical system for projecting the image, which is displayed on display element, onto viewing region of viewer. The projection optical system includes combiner that is disposed at a position in an optical path from display element to viewing region of viewer. Combiner has a surface at which light incident from display element enters; the surface has a curved surface shape. Combiner has an effective region corresponding to viewing region of viewer. In the effective region, combiner has a horizontal cross-sectional shape that changes in thickness along from the center toward an end.

Abstract: A zoom lens system includes, in order from the object side to the image side, a first lens group having negative power and a second lens group having positive power. The first lens group includes at least two negative lenses. When zooming, one of the first lens group and the second lens group is fixed relative to the imaging surface, and the other moves along an optical axis to change an angle of view.

Abstract: Head-up display includes: display element for displaying an image, and a projection optical system for projecting the image, which is displayed on display element, onto viewing region of viewer. The projection optical system includes combiner that is disposed at a position in an optical path from display element to viewing region of viewer. Combiner has a surface at which light incident from display element enters; the surface has a curved surface shape. Combiner has an effective region corresponding to viewing region of viewer. In the effective region, combiner has a horizontal cross-sectional shape that changes in thickness along from the center toward an end.

Abstract: A fixed-focus lens system includes, in order from an object side to an image side, a first lens element having negative power, the first lens element having a convex surface opposite to an object, a second lens element having positive power, the second lens element having a concave surface opposite to the object, a third lens element having positive power, a fourth lens element having negative power, and a fifth lens element having positive power. A half angle of view of the fixed-focus lens system is 50 degrees or more, and a shape of the convex surface on the object side of the first lens element has at least one inflection point at a part except for the optical axis. With this configuration, a fixed-focus lens system capable of favorably correcting various aberrations can be provided.

Abstract: A single-focal lens system includes a first lens group having positive power, an aperture diaphragm, and a second lens group having positive power, in this order from an object side to an image side. The first lens group includes a first lens element having negative power, a second lens element having negative power, and a third lens element having positive power in this order from the object side to the image side. The second lens group includes a fourth lens element having power and a fifth lens element having positive power. When fG1 is a focal length of the first lens group at a d-line, fG2 is a focal length of the second lens group at the d-line, f4 is a focal length of the fourth lens element at the d-line, f is a focal length of an entire system at the d-line, and w is a half angle of view, a condition (1), a condition (3c) and a condition (6) shown below are satisfied. 0.5<fG1/fG2<3.0??(1) 11.

Abstract: A fixed focal length lens system includes, in order from an object side to an image side, first lens element having negative power, second lens element having negative power, third lens element having positive power, fourth lens element having power, fifth lens element having power, and sixth lens element having positive power. The third lens element is a positive meniscus lens element having a convex surface on the image side. At least one of second to sixth lens elements is made of glass. The fixed focal length lens system satisfies condition (1) below: 0<(L1R2+L2R1)/(L1R2?L2R1)<100??(1) where L1R2 is a radius of curvature of an image-side surface of first lens element, and L2R1 is a radius of curvature of an object-side surface of second lens element.

Abstract: A zoom lens system includes, in order from the object side to the image side, a first lens group having negative power and a second lens group having positive power. The first lens group includes at least two negative lenses. When zooming, one of the first lens group and the second lens group is fixed relative to the imaging surface, and the other moves along an optical axis to change an angle of view.

Abstract: Head-up display includes: display element for displaying an image, and a projection optical system for projecting the image, which is displayed on display element, onto viewing region of viewer. The projection optical system includes combiner that is disposed at a position in an optical path from display element to viewing region of viewer. Combiner has a surface at which light incident from display element enters; the surface has a curved surface shape. Combiner has an effective region corresponding to viewing region of viewer. In the effective region, combiner has a horizontal cross-sectional shape that changes in thickness along from the center toward an end.

Abstract: A zoom lens system comprising a plurality of lens units each being composed of at least one lens element, and comprising, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit having positive optical power, and a fifth lens unit having negative optical power, wherein the first lens unit is composed of two or less lens elements, the third lens unit is composed of five or more lens elements, and the condition: 5.0<f1/f3<8.0 (f1: a focal length of the first lens unit, f3: a focal length of the third lens unit) is satisfied.

Abstract: An imaging optical system, in order from an object side to an image side, includes: a first lens unit having positive optical power; and a second lens unit. In focusing from an infinity in-focus condition to a close-object in-focus condition, the first lens unit moves along an optical axis, and the second lens unit is fixed with respect to an image surface. The imaging optical system is compact, sufficiently suppresses occurrence of various aberrations, has high resolution from the infinity in-focus condition to the close-object in-focus condition, is bright and highly efficient, and is suitable for wide-angle photographing.

Abstract: A zoom lens system comprising: a first lens unit having negative optical power; a second lens unit having positive optical power; and a third lens unit having positive optical power, wherein the first to third lens units are individually moved along an optical axis to vary magnification in zooming, each lens unit includes at least one lens element that satisfies the conditions: nd?1.67, vd<59 and 0.000<PgF+0.002×vd?0.664 (nd, vd and PgF: a refractive index to the d-line, an Abbe number to the d-line and a partial dispersion ratio, of the lens element), and the condition: 0.31<Ir/?(|fG1×fG2|) (Ir=fT×tan(?T), fT and ?T: a focal length of the entire system and a half value of maximum view angle, at a telephoto limit, fG1 and fG2: a focal length of each of the first lens unit and the second lens unit) is satisfied; an imaging device; and a camera are provided.

Abstract: A zoom lens system comprising a plurality of lens units each being composed of at least one lens element, and comprising, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, a fourth lens unit having positive optical power, and a fifth lens unit having negative optical power, wherein the first lens unit is composed of two or less lens elements, the third lens unit is composed of five or more lens elements, and the condition: 5.0<f1/f3<8.0 (f1: a focal length of the first lens unit, f3: a focal length of the third lens unit) is satisfied.

Abstract: A zoom lens system comprising: a negative first lens unit; a positive second lens unit; and a positive third lens unit, wherein the first to third lens units are individually moved along an optical axis to vary magnification in zooming, the first lens unit is composed of two lens elements and includes a positive lens element having at least one aspheric surface, the third lens unit is composed of one lens element, and the condition: 1.74<Ir/?{square root over ((|DL1×fG1|))} (DL1: an optical axial thickness of an object side first lens element in the first lens unit, fG1: a focal length of the first lens unit, Ir=fT×tan(?T), fT and ?T: a focal length of the entire system and a half value of maximum view angle at a telephoto limit) is satisfied; an imaging device; and a camera are provided.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and subsequent lens units including a fourth lens unit having optical power, wherein any one of the first lens unit, the second lens unit, the third lens unit, and the subsequent lens units includes a lens element having a reflecting surface that bends a light beam incident from an object, wherein in zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit and the third lens unit do not move along an optical axis, and wherein the condition is satisfied: 1.42<nd4ave<1.58 (nd4ave is an average of refractive indices to the d-line of the lens elements constituting the fourth lens unit), an imaging device and a camera are provided.

Abstract: A zoom lens system comprising: a negative first lens unit; a positive second lens unit; and a positive third lens unit, wherein the first to third lens units are individually moved along an optical axis to vary magnification in zooming, the first lens unit is composed of two lens elements and includes a positive lens element having at least one aspheric surface, the third lens unit is composed of one lens element, and the condition: 1.74<Ir/?(|DL1×fG1|) (DL1: an optical axial thickness of an object side first lens element in the first lens unit, fG1: a focal length of the first lens unit, Ir=fT×tan(?T), fT and ?T: a focal length of the entire system and a half value of maximum view angle at a telephoto limit) is satisfied; an imaging device; and a camera are provided.

Abstract: A zoom lens system comprising: a first lens unit having negative optical power; a second lens unit having positive optical power; and a third lens unit having positive optical power, wherein the first to third lens units are individually moved along an optical axis to vary magnification in zooming, each lens unit includes at least one lens element that satisfies the conditions: nd?1.67, vd<59 and 0.000<PgF+0.002×vd?0.664 (nd, vd and PgF: a refractive index to the d-line, an Abbe number to the d-line and a partial dispersion ratio, of the lens element), and the condition: 0.31<Ir/?(|fG1×fG2|) (Ir=fT×tan (?T), fT and ?T: a focal length of the entire system and a half value of maximum view angle, at a telephoto limit, fG1 and fG2: a focal length of each of the first lens unit and the second lens unit) is satisfied; an imaging device; and a camera are provided.