Optical element
AssigneeNalux Co., Ltd.
InventorKatsumoto IKEDA
Life of this patent
Estimating the term…
Abstract
An optical element includes a light receiving surface 101 covering a light source on a plane and an exit surface 103. When the central axis is AX, the intersection of AX with the plane is P0, and in a cross section containing AX, an angle between a line connecting P0 and P on 101 and AX is θr, an angle between a normal to 103 at Q and AX is φ, a distance from AX to Q is r, the maximum value of r on 103 is rmax, and θr and φ are positive when measured clockwise with respect to AX, φ has plural positive local maximum and minimum values as a function of r in 0.5rmax≦r, in an area of 103 through which a ray travelling from P0 at a positive angle θr passes, and the shape of 103 is symmetric with respect to AX.
Claims15
An optical element comprising a light receiving surface which covers a light source arranged on a plane and an exit surface which covers the light receiving surface, the optical element being configured such that lights from the light source passes through the light receiving surface and the exit surface and goes to the outside for illumination,
- wherein when the central axis of the optical element is designated as an optical axis, the point of intersection of the optical axis with the plane is designated as a point P0, and in a cross section of the optical element, the cross section containing the optical axis and being perpendicular to the plane, an angle which a line connecting the point P0 and a point on the light receiving surface forms with the optical axis is designated as θr, an angle which a normal to the exit surface at a point Q on the exit surface forms with the optical axis is designated as φ, a distance from the optical axis to the point Q is designated as r, the maximum value of distance from the optical axis to a point on the exit surface is designated as rmax, and a value of θr and a value φ are designated as positive when measured clockwise with respect to the optical axis, the exit surface is configured such that φ has plural local minimum values and plural local maximum values as a function of r in the range of
- 0.5rmax≦r,
- and the plural local minimum values and the plural local maximum values are positive in an area of the exit surface through which a ray that is emitted from the point P0 and travels at a positive angle of θr passes, and the shape of the exit surface is symmetric with respect to the optical axis.
An optical element comprising a light receiving surface which covers a light source arranged on a plane and an exit surface which covers the light receiving surface, the optical element being configured such that lights from the light source passes through the light receiving surface and the exit surface and goes to the outside for illumination,
- wherein when the central axis of the optical element is designated as an optical axis, the point of intersection of the optical axis with the plane is designated as a point P0, the point of intersection of the optical axis with the light receiving surface is designated as O1 and in a cross section of the optical element, the cross section containing the optical axis and being perpendicular to the plane, an angle which a line connecting the point P0 and a point P on the light receiving surface forms with the optical axis is designated as θr, the direction of a ray which leaves the optical element after having traveled from the point P0 to the point P forms with the optical axis is designated as θe, and the point P is moved from the point O1 along the light receiving surface, the optical element is configured such that θe has plural local minimum values and plural local maximum values as a function of θr in the range of
- 60 degrees≦θe,
- and the shape of the exit surface is symmetric with respect to the optical axis.
Dependencies are inferred from the claim text.