A lens for an illumination device includes a lens 1 having a first surface 11 and a second surface 12 connected to each other along an annular curved line 14 which is composed of two symmetric curved lines 15. The two symmetric curved lines 15 are connected to each other at a first point 151 and a second point 153. Each of the two curved lines 15 has a middle point 152. The first surface 11 is a multiple-focus surface and located on the outer side of the lens 1. The patterns and paths of the light beams can be controlled by the first surface 11 of the lens 1.

Refractive optical element for athermalizing an infrared imaging system, said element being detachably mounted to the latter and having a circular base and a convex surface with an helical profile, the radial jog of which ascending helically from the lower edge (1) to the upper edge (2) of the jog.

A projection type display apparatus including an oblique projection optical system having a plurality of lenses is disclosed. A lens nearest to a projection screen has a vertical effective image area through which a light flux (3) passes. The lens is arranged at a position not including an optical axis (11) shared by the largest number of lenses among the plurality of lenses. A flat mirror (14) for returning the optical path is arranged between the particular lens and the projection screen at a predetermined angle to the optical axis (11). An enlarged image obtained by the light flux (3) returned by the flat mirror (14) is formed toward a display screen.

A collimation lens system (100) for converging the light from an LED (30) into a light beam (L), comprises:

a central lens (10) aligned along an optical axis (X) with the LED (30) for converging inner light from the LED (30), the central lens (10) comprising an aspheric collimation plano convex lens (10) having a planar entrance surface (11) and an aspheric exit surface (12); and

a peripheral lens (20) surrounding the central lens (10) for converging outer light from the LED (30), the peripheral lens (20) comprising a total internal reflection collimation lens having an entrance surface (21) and an exit surface (22) and including a high order aspheric total internal reflection surface (23) for reflecting said outer light by way of total internal reflection.

The central lens (10) and the peripheral lens (20) share a common focal point at which the LED (30) may be positioned.

A luminaire and a method of operating a luminaire is provided. The luminaire includes a light source emitting a plurality of light rays. A collimation device is arranged to receive a portion of light from the light source and transmits the portion of light through an exit aperture towards an illuminated area. The exit aperture includes a planar portion and at least one lenslet formed thereon. The lenslet is arranged having a first profile and a second profile, where the portion of light is refracted on a plurality of angles to form a twisted profile by the lenslet.

A focusing lens (100) for an LED (2), which concentrates light emitted from the LED (2) so as to have directionality parallel to an optic axis (4), comprises: a transparent body (110); a first lens part (200) formed in the body; and a second lens part (300) covering the first lens part (200), and wherein the first lens part (200) comprises: parallel first and second convex aspheric lens surfaces (210,220), and wherein the second lens part (300) comprises: a plane of incidence (310) formed to protrude from an outer circumference of the first aspheric lens surface (210), the plane of incidence (310) into which the LED (2) is inserted and which is configured to allow the light emitted from the LED (2) to be incident and refracted; a plane of reflection (320) formed to have a convex curved surface which extend and slopes to be progressive wider from the plane of incidence (310) towards the second aspheric lens surface (220), the plane of reflection (320) which is configured to allow the light emitted from the LED (2) to be totally reflected; and a plane of emission (330) formed to have a concave curved surface which extends and slopes from the plane of reflection (320) towards the second aspheric lens surface (220), the plane of emission (330) which is configured to allow the light emitted from the LED (2) to be refracted and emitted as light being parallel to the optic axis (4). The focusing lens minimizes loss of the light emitted from the LED (2) and maximally reduces an angle of the emitted light, to effectively illuminate a local region at a long distance.

A non-cylindrically surfaced lens converts a collimated light beam into a light plane that increases a light intensity toward distal portions of the light plane's arc so as to substantially uniformly project a reference light line onto a reference surface onto which the light plane is projected. The non-cylindrically surfaced lens has first and second surfaces that remain constant over at least a portion of the z direction length of the lens. The second surface defines a multiple-radius curve in an x,y plane. The lens may be incorporated into a self-leveled optical device that projects a reference light line onto a reference surface at a predetermined angle relative to horizontal.

A lens is disclosed. The lens includes an optical element made of a material exhibiting a positive refractive index, and a medium exhibiting negative refraction formed on the optical element serving as a substrate.

A lens for a wet environment lighting device that has a fixture with an interior that has an opening, and at least one light source located within the fixture interior. Light from the light source proceeds out through the opening. The lens is for location in front of the fixture and the light source located therein and the lens encloses the opening from the wet environment. The lens has a first light-directing area for directing light in a first beam pattern. The lens also has a second light-directing area, distinct from the first light-directing area, for directing light in a second beam pattern, distinct from the first beam pattern. The lens is positioned relative to fixture and light source therein to select from the distinct beam patterns based on the alignment of the light-directing areas relative to the light source resulting from a positioning of the lens.

The present invention provides an athermalized optical element that does not require auxiliary material to compensate for the rate of change of the refractive index with temperature, which can be widely applied to both transparent materials of inorganic material and organic material, and is formed without decrease of transparency and dimension distortion.

The optical element of the present invention is an optical element for controlling light propagation including: transparent material; and inorganic fine particles dispersed in the transparent material, wherein the transparent material and the inorganic fine particles meet at least one of following a) and b):

• a) a rate of change of a refractive index of the transparent material with temperature and a rate of change of a refractive index of the inorganic fine particles with temperature are opposite in sign;
• b) a thermal expansion coefficient of the transparent material and a thermal expansion coefficient of the inorganic fine particles are opposite in sign.