Abstract: The projector-type headlamp comprises a projection lens unit and a light source unit. A diffraction grating designed to eliminate chromatic aberrations is provided on at least part of a lens surface of the lens unit. When an x axis in the horizontal direction and a y axis in the vertical direction are defined on a plane perpendicular to the optical axis, R1 is the maximum y coordinate on the lens surface, and 0?A<1, an area of the lens surface in which y<A·R1 comprises a curved surface or a flat surface, at least partially provided with the diffraction grating, and an area of the lens surface in which y?A·R1 comprises a separate curved surface that has a power greater than the power of the curved surface or flat surface, and is not provided with a diffraction grating.

Abstract: The projector-type headlamp comprises a projection lens unit and a light source unit. A diffraction grating designed to eliminate chromatic aberrations is provided on at least part of a lens surface of the lens unit. When an x axis in the horizontal direction and a y axis in the vertical direction are defined on a plane perpendicular to the optical axis, R1 is the maximum y coordinate on the lens surface, and 0?A<1, an area of the lens surface in which y<A·R1 comprises a curved surface or a flat surface, at least partially provided with the diffraction grating, and an area of the lens surface in which y?A·R1 comprises a separate curved surface that has a power greater than the power of the curved surface or flat surface, and is not provided with a diffraction grating.

Abstract: An optical element has a light receiving surface covering a light source arranged on a plane and an exit surface covering the light receiving surface. When an axis passing through the center of the light source and is perpendicular to the plane is designated as an optical axis and the point of intersection of the optical axis and the light receiving surface is designated as O1, the light receiving surface is concaved around the optical axis with respect to the periphery. When an angle which a normal to the light receiving surface on a point P thereon forms with the optical axis is designated as ?h and distance in the optical axis direction from O1 to P is designated as z, ?h has at least one local maximum value and at least one local minimum value with respect to z while P is moved along the light receiving surface.

Abstract: An optical element has a light receiving surface covering a light source arranged on a plane and an exit surface covering the light receiving surface. When an axis passing through the center of the light source and is perpendicular to the plane is designated as an optical axis and the point of intersection of the optical axis and the light receiving surface is designated as O1, the light receiving surface is concaved around the optical axis with respect to the periphery. When an angle which a normal to the light receiving surface on a point P thereon forms with the optical axis is designated as ?h and distance in the optical axis direction from O1 to P is designated as z, ?h has at least one local maximum value and at least one local minimum value with respect to z while P is moved along the light receiving surface.

Abstract: An imaging optical system includes three reflecting mirrors having first to third reflection surfaces and is configured, such that in an XYZ orthogonal coordinate system using an optical axis at the center of the field of view as Z-axis, the optical axis at the center of the field of view and an optical axis of an image plane are in parallel to each other Assuming that along the path of the beam traveling along the optical axis at the center of the field of view a distance between the second reflection surface and the third reflection surface is L2, a distance between the third reflection surface and the image plane is L3 and fy1 and an equivalent F-number of the imaging optical system is represented as Fno, the relational expression 0.5<Fno(L2/L3)<1.3 is satisfied.

Abstract: An imaging optical system includes three reflecting mirrors having first to third reflection surfaces and is configured, such that in an XYZ orthogonal coordinate system using an optical axis at the center of the field of view as Z-axis, the optical axis at the center of the field of view and an optical axis of an image plane are in parallel to each other by changing orientation of the optical axis in a YZ section while maintaining the orientation of the optical axis in an XZ section. At least one of the three reflection surfaces is rotationally asymmetric. Assuming that along the path of the beam traveling along the optical axis at the center of the field of view a distance between the second reflection surface and the third reflection surface is L2, a distance between the third reflection surface and the image plane is L3 and fy1 and an equivalent F-number of the imaging optical system is represented as Fno, the relational expression 0.5<Fno(L2/L3)<1.3 is satisfied.

Abstract: An imaging optical system capable of moving a meridian image plane further closer to an ideal imaging plane vertical to an optical axis with the number of lenses kept constant. At least one plane of at least one optical element and including at least one optical element is divided into at least one zonal area surrounding an optical axis and a center area including the optical axis.

Abstract: An imaging optical system capable of moving a meridian image plane further closer to an ideal imaging plane vertical to an optical axis with the number of lenses kept constant. At least one plane of at least one optical element and including at least one optical element is divided into at least one zonal area surrounding an optical axis and a center area including the optical axis.

Abstract: There is provided an axially asymmetric beam shaping optical system causing no astigmatism for variation in refractive index incident to an external cause, e.g. variation in wavelength of a light source or variation in ambient temperature. The system has a diffraction grating plane as follows. Assuming the optical axis is the z-axis and a plane perpendicular to the optical axis is the xy plane, the phase function in the x-axis direction and the y-axis direction of the diffraction grating plane is determined to minimize astigmatism by equalizing variation in distance from the light source to an image forming point or a virtual image point on the xz plane and variation in that distance on the yz plane. Furthermore, the system has a diffraction grating plane as follows.

Abstract: To provide a compact imaging optical system using reflecting mirrors that can be equipped and used in a vehicle or the like. An imaging optical system according to the invention includes three reflecting mirrors (103, 107, 109) and configured, when an XYZ orthogonal coordinate system using an optical axis at the center of the field of view as Z-axis is determined, so that the optical axis at the center of the field of view and an optical axis of an image surface may be in parallel by changing orientation of the optical axis in a YZ section while maintaining the orientation of the optical axis in an XZ section, wherein a shape of a YZ section of at least one reflecting mirror is made asymmetric with respect to Z-axis of local coordinates of each reflection surface for reducing aberration.

Abstract: A beam-shaping optical element employing an aspherical profileis presented to minimize aberration. A beam-shaping optical element according to the present invention includes an entrance surface and the exit surface, both having a non-circular cross-section in any plane comprising the optical axis. A beam-shaping optical element according to one embodiment of the present invention, has the optical axis coinciding with the Z-axis of a three-axis rectangular XYZ system of coordinates, and the entrance surface and/or the exit surface represented by a mathematical equation comprising a term representing a non-rotationally symmetric aspherical profile, at least one correction term comprising a function of variable X alone and at least one correction term comprising a function of variable Y alone.

Abstract: A beam-shaping optical element employing an aspherical profileis presented to minimize aberration. A beam-shaping optical element according to the present invention includes an entrance surface and the exit surface, both having a non-circular cross-section in any plane comprising the optical axis. A beam-shaping optical element according to one embodiment of the present invention, has the optical axis coinciding with the Z-axis of a three-axis rectangular XYZ system of coordinates, and the entrance surface and/or the exit surface represented by a mathematical equation comprising a term representing a non-rotationally symmetric aspherical profile, at least one correction term comprising a function of variable X alone and at least one correction term comprising a function of variable Y alone.