A pair of moulds for moulding an optical component is disclosed. The pair of moulds includes a first mould having a first surface, and a second mould having a second surface. The first surface includes a moulding portion for moulding a first optical surface of the optical component, and an alignment portion for alignment with the second mould. The alignment portion extends around the moulding portion. The second surface includes a moulding portion for moulding a second, opposite optical surface of the optical component, and an alignment portion for alignment with the first mould via a contact with the alignment portion of the first surface. When the moulds are brought together, they self-align. A corresponding moulding apparatus and a method may use the mould pair to manufacture various optical components.

Disclosed in the present invention is a beam coherence eliminating element. The optical medium material of the element comprises microcrystalline glass, wherein microcrystalline particles therein have a size of 0.1-1000 nm and are distributed randomly. As the crystals in the microcrystalline glass can change the phase of light beams, the microcrystalline glass can change the phase of the light beams randomly, thereby eliminating the coherence of the beams. The crystal size of the microcrystalline glass is small, and thus does not affect the transmission efficiency of light beams. The element of the present invention has a simple structure and is convenient to use, and can be added in the process of beam transmission to easily eliminate beam coherence.

A lens unit includes a positive lens element provided with a convex surface on an incident surface and/or an exit surface; and a lens frame supporting the lens element and being provided with a projection that projects in an inner radial direction from inside the lens frame. The lens frame supports the lens element with the projection fixedly fitted into an outer peripheral portion of the lens element. The projection is provided, on an inner peripheral portion thereof, with a first surface positioned on an incident side in an optical axis direction, a second surface positioned on an exit side in the optical axis direction, and a third surface positioned between the first surface and the second surface. The first, second and third surfaces are tapered surfaces that are respectively inclined relative to the optical axis direction. A method of manufacturing the lens unit is also provided.

A lens unit includes a positive lens element provided with a convex surface on an incident surface and/or an exit surface; and a lens frame supporting the lens element and being provided with a projection that projects in an inner radial direction from inside the lens frame. The lens frame supports the lens element with the projection fixedly fitted into an outer peripheral portion of the lens element. The projection is provided, on an inner peripheral portion thereof, with a first surface positioned on an incident side in an optical axis direction, a second surface positioned on an exit side in the optical axis direction, and a third surface positioned between the first surface and the second surface. The first, second and third surfaces are tapered surfaces that are respectively inclined relative to the optical axis direction. A method of manufacturing the lens unit is also provided.

The present disclosure relates to a mold for glass forming, wherein the mold comprises a ceramic material, and wherein the ceramic material comprises aluminum nitride and hexagonal boron nitride, and wherein the ceramic material comprises from 50 to 80% by weight of aluminum nitride and from 20 to 50% by weight of hexagonal boron nitride, based on the total weight of the ceramic material. The present disclosure further relates to a process for using such molds to form curved glass plates.

The invention relates to an optical element for a vehicle headlight, in particular a motor vehicle headlight, having a first head lens array which is a compressed as a single piece from a transparent material and at least one second head lens array which is compressed as a single piece from the same or another transparent material. Said first head lens array and the second head lens array have respectively a connecting web which connects the at least one first head lens to a second head lens.

The invention relates to an optical element for a vehicle headlight, in particular a motor vehicle headlight, having a first head lens array which is a compressed as a single piece from a transparent material and at least one second head lens array which is compressed as a single piece from the same or another transparent material. Said first head lens array and the second head lens array have respectively a connecting web which connects the at least one first head lens to a second head lens.

The present invention provides a microcrystalline glass and microcrystalline glass product with excellent mechanical properties, microcrystalline glass product, the components of which, expressed in weight percent, contain: SiO.sub.2: 65 ∼80%; AI.sub.2O.sub.3: below 5%; Li.sub.2O: 10 ∼25%; ZrO.sub.2: 5 ∼15%; P.sub.2O.sub.5: 1 ∼8%. Through the reasonable component design, the microcrystalline glass product obtained by the present invention have excellent mechanical properties.

The method for manufacturing a plate glass is a method for manufacturing the plate glass having sides of at least 30 cm or more and a surface thereof on which a predetermined shape is formed. In the manufacturing method, the flat plate glass is heated to a temperature which is lower than a softening point and at which the heated flat plate glass is deformable by being pressed at a predetermined pressure or higher, the heated flat glass, which has been molded by pressing the flat plate glass with a die having a die structure for forming the predetermined shape, is cooled to the strain point while being held with the die. Further, in the manufacturing method, the pressing is performed with the die having a coefficient of thermal expansion whose difference from that of the plate glass is 2.0×10.sup.−6/K or less.

The method for manufacturing a plate glass is a method for manufacturing the plate glass having sides of at least 30 cm or more and a surface thereof on which a predetermined shape is formed. In the manufacturing method, the flat plate glass is heated to a temperature which is lower than a softening point and at which the heated flat plate glass is deformable by being pressed at a predetermined pressure or higher, the heated flat glass, which has been molded by pressing the flat plate glass with a die having a die structure for forming the predetermined shape, is cooled to the strain point while being held with the die. Further, in the manufacturing method, the pressing is performed with the die having a coefficient of thermal expansion whose difference from that of the plate glass is 2.0×10.sup.−6/K or less.