Abstract: A zoom lens system includes at least six lens groups, each of which has power. An interval between each pair of lens groups that are adjacent to each other among the at least six lens groups changes while the zoom lens system is zooming. Each of three lens groups, which are respectively located closest, second closest, and third closest to an image plane, out of the at least six lens groups consists of one or more bonded lenses.

Abstract: A lens system that forms an image on an imaging element, includes: first to third lens element arranged in order; a diaphragm; and a lens element on the image surface side. At least one of the first and second lens elements has a free-curved surface, and one of the first and second lens elements has free-curved surfaces on both sides. The third lens element has free-curved surfaces on both sides. The first lens element has a convex shape, toward the object side, of a surface facing the object side. The second lens element has a convex shape, toward the object side, of a surface facing the image surface side. The third lens element has a convex shape, toward the image surface side, of a surface facing the object side. The lens element on the image surface side has, at least on the object side, a free-curved surface.

Abstract: An eyepiece optical system has an optical axis for guiding a light beam between a pupil of a user and a display surface, and includes: a first lens element having, on a display side, a polarizing reflective surface reflecting or transmitting an incident light beam according to polarization of the incident light beam; and a second lens element disposed between the first lens element and the display surface, and having a partial reflection surface reflecting a part of the incident light beam and transmitting a remaining part thereof. The first lens element has, on a pupil side, an aspherical surface including a convex region having a convex shape opposite to the polarizing reflective surface with the optical axis being positioned therein. The aspherical surface satisfies 0.05<SagH/BF<0.25 with a sag amount SagH at a maximum image height of the display surface and a back focus BF of the eyepiece optical system.

Abstract: A lens system forms an image on an imaging element having a quadrilateral shape disposed on an optical axis. The lens system includes a second free-curved lens being asymmetrical with respect to the optical axis. A sag amount of the second free-curved lens in a circle separated from the optical axis by a length having a predetermined ratio with respect to a minimum image height has extrema outside of a first intersection points between a first surface passing through the optical axis and parallel to longer sides of the imaging element and the circle, and a second intersection point between a second surface passing through the optical axis and parallel to shorter sides of the imaging element and the circle. Each of the extrema is greater than the sag amount at the first intersection point or the second intersection point by 0.01 mm or greater.

Abstract: A lens system is configured to form an image on an imaging element having a quadrilateral shape disposed on an optical axis, and includes a first free-curved lens being asymmetrical with respect to the optical axis. A free-curved surface of the first free-curved lens has positive refractive power at an intersection point between a circle separated from the optical axis by a length having a predetermined ratio with respect to a minimum image height and a first surface passing through the optical axis and parallel to longer sides of the imaging element, and negative refractive power at an intersection point between a circle separated from the optical axis by a length having the predetermined ratio with respect to the minimum image height and a second surface passing through the optical axis and parallel to shorter sides of the imaging element.

Abstract: A zoom lens system includes at least six lens groups, each of which has power. An interval between each pair of lens groups that are adjacent to each other among the at least six lens groups changes while the zoom lens system is zooming. Each of three lens groups, which are respectively located closest, second closest, and third closest to an image plane, out of the at least six lens groups consists of one or more bonded lenses.

Abstract: A lens system includes a plurality of lens elements arranged from an object side to an image plane side, and a diaphragm arranged between the plurality of lens elements. The plurality of lens elements include a plurality of freeform lenses each having a freeform surface that is asymmetrical with respect to a first direction and a second direction which cross with each other. At least one freeform lens is placed on the image plane side of the diaphragm. With a lens thickness T1 in the first direction at a maximum height of an axial ray and a lens thickness T2 in the second direction at the maximum height of the axial ray, at least one freeform lens satisfying 0.3<T1/T2<0.76 is placed on the object side of the diaphragm.

Abstract: A lens system includes lens elements and a diaphragm. The lens elements include freeform lenses each having a freeform surface asymmetrical with respect to first and second directions. At least one freeform lens is placed on the image plane side of the diaphragm. The lens system satisfies a following conditional expression (1); 0.0075 < ? ? k = 1 N ? { ( SAG ? ? 1 k - SAG ? ? 2 k ) × ? ? ? nd k } Y ? ? 2 × tan ? ? ? ? ? 1 ? ( 1 ) where N: a total number of the freeform surfaces on the object side of the diaphragm, k: a number indicating a freeform surface among the N freeform surfaces, SAG1k, SAG2k: a sag amount at a position where a height of a k-th freeform surface in the first or second direction is 40% of an image height in the first direction, Y2: an image height in the second direction, ?1: a full angle of view in the first direction, and ?ndk: a difference between refractive indexes on the both sides of the k-th freeform surface.

Abstract: A lens system is configured to form an image on an imaging element having a quadrilateral shape disposed on an optical axis, and includes a first free-curved lens being asymmetrical with respect to the optical axis. A free-curved surface of the first free-curved lens has negative refractive power at an intersection point between a circle separated from the optical axis by a length having a predetermined ratio with respect to a minimum image height and a first surface passing through the optical axis and parallel to longer sides of the imaging element, and positive refractive power at an intersection point between a circle separated from the optical axis by a length having the predetermined ratio with respect to the minimum image height and a second surface passing through the optical axis and parallel to shorter sides of the imaging element. The predetermined ratio ranges from 40% to 80% inclusive.

Abstract: A lens system includes, in order from an object side to an image plane side: a first lens element having a negative power; a second lens element whose concave surface faces the object side; and a third lens element having a positive power, and satisfies conditions (1) and (2). 0.205<|(TL1/TA)·tan(?)|??(1) 0.120<IH/TA<0.170??(2) where TL1 is a central thickness of the first lens element, TA is a total optical length, ? is a half angle of view, and IH is an image height of the lens system.

Abstract: An imaging apparatus is attached to a side of a moving body (for example, vehicle). The imaging apparatus includes an image sensor and an optical system that forms a subject image in a range of a predetermined vertical view angle and a predetermined horizontal view angle on an imaging surface. The optical system forms an image on the imaging surface so as to cause resolution in first region (R1) of the imaging surface to be higher than resolution in second region (R2) different from the first region. A position of center (G1) of first region (R1) is at least one of a position horizontally shifted from a center of the horizontal view angle and a position vertically shifted from a center of the vertical view angle.

Abstract: An imaging system includes: a first imaging apparatus including a first imaging element and a first optical system; and a generator that generates an image based on image data acquired from the first imaging element. The first optical system includes a first free-form surface lens that has a shape that allows an image to be formed on the first imaging element such that a resolution is different between a portion of a predetermined region and another portion of the predetermined region, the resolution being defined as a total number of imaging pixels that capture an image within a unit field angle on a horizontal plane.

Abstract: A head-mounted display device includes a first display portion disposed in front of a pupil of a viewer and displaying a first image, a second display portion disposed on an ear side of the viewer and diagonally in front of the pupil and displaying a second image, a first lens disposed between the pupil and the first display portion for projecting a first image onto the pupil, and a second lens disposed between the pupil and the second display portion for projecting a second image onto the pupil. The second lens is disposed adjacent to the first lens on the ear side of the viewer, and an optical axis of the first lens and an optical axis of the second lens intersect with each other at an angle ranging from 30 degrees to 80 degrees inclusive.

Abstract: An imaging device includes a free-form lens having a shape in which (i) in a long-side direction of an imaging element, a resolution that changes along an optical axis long-side resolution curve, and the resolution that changes along a distant point long-side resolution curve in a position away from an optical axis, (ii) in a short-side direction, the resolution that changes along an optical axis short-side resolution curve, and the resolution that changes along a distant point short-side resolution curve in the position away from the optical axis, (iii) the distant point long-side resolution curve follows a shape of the optical axis long-side resolution curve, and has a higher resolution than the optical axis long-side resolution curve, and (iv) the distant point short-side resolution curve follows a shape of the optical axis short-side resolution curve, and has a higher resolution than the optical axis short-side resolution curve.

Abstract: An imaging apparatus is attached to a side of a moving body (for example, vehicle). The imaging apparatus includes an image sensor and an optical system that forms a subject image in a range of a predetermined vertical view angle and a predetermined horizontal view angle on an imaging surface. The optical system forms an image on the imaging surface so as to cause resolution in first region (R1) of the imaging surface to be higher than resolution in second region (R2) different from the first region. A position of center (G1) of first region (R1) is at least one of a position horizontally shifted from a center of the horizontal view angle and a position vertically shifted from a center of the vertical view angle.

Abstract: An imaging optical system is an optical system having an image circle formed on an imaging element. The imaging optical system includes: a plurality of lens elements arranged from an object side to an image plane side, and a diaphragm arranged between the plurality of lens elements. The plurality of lens elements includes a freeform lens having a freeform surface that is asymmetrical between a first direction and a second direction which cross with each other. At least two freeform lenses are located on the object side of the diaphragm.

Abstract: An imaging optical system having an image circle formed on an imaging element includes: a plurality of lens elements arranged from an object side to an image plane side, and a diaphragm arranged between the plurality of lens elements, wherein the plurality of lens elements includes a freeform lens having a freeform surface that is asymmetrical with respect to a long side direction and a short side direction which cross with each other with a diameter of the image circle in the long side direction being larger than a diameter of the image circle in the short side direction, wherein at least two freeform lenses are located on the object side of the diaphragm, wherein the imaging optical system satisfies a condition based on a summation for freeform surfaces of freeform lenses located on the object side of the diaphragm.

Abstract: An imaging apparatus is attached to a side of a moving body (for example, vehicle). The imaging apparatus includes an image sensor and an optical system that forms a subject image in a range of a predetermined vertical view angle and a predetermined horizontal view angle on an imaging surface. The optical system forms an image on the imaging surface so as to cause resolution in first region (R1) of the imaging surface to be higher than resolution in second region (R2) different from the first region. A position of center (G1) of first region (R1) is at least one of a position horizontally shifted from a center of the horizontal view angle and a position vertically shifted from a center of the vertical view angle.

Abstract: A lens system that forms an image on an imaging element, includes: first to third lens element arranged in order; a diaphragm; and a lens element on the image surface side. At least one of the first and second lens elements has a free-curved surface, and one of the first and second lens elements has free-curved surfaces on both sides. The third lens element has free-curved surfaces on both sides. The first lens element has a convex shape, toward the object side, of a surface facing the object side. The second lens element has a convex shape, toward the object side, of a surface facing the image surface side. The third lens element has a convex shape, toward the image surface side, of a surface facing the object side. The lens element on the image surface side has, at least on the object side, a free-curved surface.

Abstract: An imaging device having an optical system including a free-form surface lens with rotationally asymmetric shape that forms an image on an imaging surface such that a resolution of a first region in front of the predetermined region is higher than a resolution of a second region at a lateral side of the predetermined region. The free-form surface lens has a shape that forms the image such that a resolution of a portion at a predetermined first distance away from a center of the first region in a vertical direction is different from a resolution of a portion at the predetermined first distance away from the center of the first region in a horizontal direction, the vertical direction being orthogonal to the horizontal direction, in the imaging element, in which the first region and the second region are aligned.