An optical lens device for a head-mounted display includes a transparent support substrate and a Fresnel lens disposed thereon. The Fresnel lens includes a central lens element and a plurality of prismatic elements arranged relative to the central lens element in a proximal-to-distal manner. Each of the prismatic elements has a base facing toward the support substrate, and a draft facet and a sloped facet extending from the base away from the support substrate to intersect with each other to form an apex. Each of the prismatic elements has a height measured from the base to the apex and not greater than 75 μm. The base has a width not greater than 250 μm. A method and a mold for producing the optical lens device are also disclosed.

A pressure-sensitive adhesive tape for molding a plastic lens having a substrate and a pressure-sensitive adhesive layer formed on a surface of the substrate. The pressure-sensitive adhesive layer includes an acrylic copolymer having a functional group and a crosslinking agent capable of reacting with the functional group; the acrylic copolymer has a weight-average molecular weight (M.sub.w) of 1,100,000 or more and a molecular-weight polydispersity (M.sub.w/M.sub.n) of 10.0 or less; the pressure-sensitive adhesive layer has an elution percentage of 48.0% or less when immersed for two hours in toluene the temperature of which being adjusted to 80° C.; the pressure-sensitive adhesive tape exhibits a shift length of 0.15 mm or more and 0.50 mm or less after 800 minutes in a creep test; and the plastic lens has a refractive index of 1.59 or more.

In a method of manufacturing an achromatic lens according to an embodiment of the present disclosure, the achromatic lens in which a first lens and a second lens are integrally molded is manufactured by using mold processing, so that chromatic aberration correction ability may be improved without using an adhesive or a separate instrument to fix the first lens and the second lens to each other.

The present invention provides a concave diffraction grating capable of improved diffraction efficiency by suppressing spherical aberration. The concave diffraction grating is a concave diffraction grating 2 for dispersing and focusing light and comprises sawtooth grating grooves 21 on a concave substrate 24, with the sawtooth grating grooves 21 being unequally spaced. The concave diffraction grating 2 for dispersing and focusing light is formed by preparing a planar diffraction grating with a sawtooth shape which is formed on a planar substrate by photo-lithography and etching or machining and which forms unequally spaced grating grooves 21, deforming and mounting the planar diffraction grating along a fixed convex substrate to obtain a mold of a concave diffraction grating, and transferring the mold of the concave diffraction grating to the surface of a metal or a resin.

An optical device (201) comprises a lens (205) having a light ingress surface (206) and a light egress surface (207). The light ingress surface comprises one or more V-shaped projections on a center area (208) of the light ingress surface and the light ingress surface is free from corners on areas (209) outside the center area. Each V-shaped projection is shaped so that a surface penetration takes place when a light beam arrives at a side surface of the V-shaped projection and a total internal reflection takes place when the light beam arrives at the other side surface of the V-shaped projection. Thus, obliquely arriving light beams emitted by edge areas of a light emitting surface (213) of a light source (202) are mixed better with light beams emitted by other areas of the light emitting surface. Therefore, undesired color variations within a light distribution pattern are reduced.

Exemplary embodiments of the present disclosure provide a method and apparatus for forming an ophthalmic lens. An exemplary method includes providing a plurality of posterior tools each having a posterior optic defining surface and a plurality of anterior tools each having an anterior optic defining surface, wherein each one of the plurality of posterior tools has a different central posterior optic defining surface including a unique conic section. The method further includes selecting one of the plurality of posterior tools and one of the plurality of anterior tools based on a criteria, and forming a posterior mold by the selected one of the plurality of posterior tools and an anterior mold by the selected one of the plurality of anterior tools, the posterior mold and the anterior mold operable to form an ophthalmic lens having the criteria.

A mold unit (22) for molding ophthalmic lenses comprises: an adapter piece (220) comprising an opening (2200) extending around a longitudinal axis (2201); a sleeve (221) fixedly connected to the adapter piece (220) and extending through the opening (2200) of the adapter piece (220); a lens mold (222) rigidly mounted to the sleeve (221); an adjustment ring (224) firmly attached to the sleeve (221) to circumferentially surround a portion of the sleeve (221).

The adjustment ring (224) comprises a flat circular outer engagement surface (2244), and the adapter piece (220) comprises at least one clamping block (2211) having a flat inner clamping surface (2214). The flat inner clamping surface (2214) frictionally clamps the flat circular outer engagement surface (2244) to prevent inadvertent rotation of the sleeve (221) relative to the adapter piece (220) but to allow rotation of the sleeve (221) relative to the adapter piece (220) upon the application of a torque higher than a predetermined threshold torque.

A method for making glass material lens array, comprising: Step 1: providing a mold device, an upper mold, a lower mold a plate structure having plate body and through holes, and a plurality of lenses having lens body portions and annular portions; Step 2: placing the plurality of lenses on the lower mold cavities of the lower mold; Step 3: disposing the plate structure between the upper mold and the lower mold, to align the through holes with the lenses; Step 4: moving the plate structure downward, to have the lenses received within the through holes; Step 5: closing the upper mold and the lower mold, to make the upper mold pressing region abut and press the plate body; and Step 6: forcing and squeezing the plate body of the plate structure to deform, and generate a deformed region B flowing and covering a periphery of the annular portion.

A method includes pressing a face of a stamp into a first portion of a replication material disposed on a substrate, to cause the replication material to have a predetermined characteristic, exposing the first portion of the replication material to illumination, to modify the first portion of the replication material, and subsequently removing a second portion of the replication material that was not exposed to the illumination. An optical device includes a substrate, a portion of replication material disposed on a first surface of the substrate, the portion of replication material forming one or more diffractive optical elements, and a masking layer disposed on a second surface of the substrate, the second surface being opposite the first surface, in which a sidewall of the replication material has a straight profile, and in which the masking layer defines an aperture aligned with the portion of the replication material.

A method of manufacturing a plastic lens includes first heating of a lens preform, disposing the lens preform in a molding apparatus, second heating of the lens preform, pressing the lens preform with the molding apparatus, and cooling the molding apparatus.