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.

A method of fabricating a shaped optical element for refracting infrared light. The method can include providing a chalcogenide glass mass within a precision mold, the chalcogenide glass mass having a starting volume that is equal to or less than about 105% of the volume of the shaped optical element, precision molding the chalcogenide glass mass by providing heat and pressure to form the chalcogenide glass mass into a near-net shaped optical element, removing the near-net shaped optical element from the precision mold, and refining the near-net shaped optical element to generate the shaped optical element, the outside diameter of the near-net shaped optical element being less than or equal to 25 μm larger than an outside diameter of the shaped optical element. The near-net shaped optical element can have an outside diameter less than 20 μm greater than the outside diameter of the shaped optical element.

A method of molding an optical element includes: preparing a molding material; preparing an upper mold having an upper surface molding surface, a lower mold having a lower surface molding surface, and a side mold having a side surface molding surface; inserting a neck portion of the upper mold and a neck portion of the lower mold into a hole portion of the side mold; positioning a distal end of the neck portion of the lower mold below an opening rim of the hole portion, and electing oxygen that is in the molds through a gap formed between the opening rim of the hole portion and the molding material that has been placed on the lower surface molding surface; heating up the molding material; and press molding the molding material by bringing the upper mold and side mold, and the lower mold, closer to each other.

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.

An optical element manufacturing apparatus includes plural pairs of stage units that are each arranged opposite to each other so as to sandwich a mold set that houses a molding material, each of the plural pairs of stage units performing at least one of heating, pressurization, and cooling on the mold set, wherein each of the stage units includes a temperature control block for which temperature is controlled, and in a third direction orthogonal to a first direction and a second direction, the temperature control block includes heating regions that are positioned on sides of both ends and in which heating sources are arranged, and a non-heating region that is positioned on a central side and in which the heating sources are not arranged throughout the first direction, the first direction being a direction in which the plural pairs of stage units are arranged, and the second direction being a direction in which a pair of stage units are opposite to each other.

A method of producing an optical element includes: determining, as a reference mold set, a first mold set from among mold sets; determining a set temperature for the reference mold set; acquiring reference data by measuring, by a temperature measurement sensor, a temperature of the reference mold set; measuring, by the temperature measurement sensor, a temperature of a second mold set that is at least one of the mold sets other than the reference mold set; calculating a correction value based on a measurement result obtained by the measuring and on the reference data; determining a set temperature for the second mold set based on the set temperature for the reference mold set and on the correction value; and performing temperature control on the mold sets based on set temperatures determined for the respective mold sets to produce the optical elements.

An optical element shaping mold set includes a first shaping mold and a second shaping mold that face each other; a tubular third shaping mold which is located around the first shaping mold and the second shaping mold and in which at least one of the first shaping mold and the second shaping mold slides, and heating, pressing and cooling are conducted with a shaping-target material accommodated between the first shaping mold and the second shaping mold, the third shaping mold has a slit formed on at least one of ends in a sliding direction of the at least one of the first shaping mold and the second shaping mold, and the third shaping mold has a linear expansion coefficient that is smaller than a linear expansion coefficient of the first shaping mold and smaller than a linear expansion coefficient of the second shaping mold.

An optical element molding mold set includes a first mold and a second mold that are opposite to each other, and a third mold that is located on an outer periphery of a cavity between the first mold and the second mold, and an inner peripheral surface of the third mold has different friction coefficients between one side and another side in an opposite direction of the first mold and the second mold.

A method for manufacturing a hollow glass is provided. The method includes the steps of placing at least one drop of glass in a cavity of a mold, inserting a punch into the cavity of the mold, forming the hollow glass item by using the punch and simultaneously imprinting at least one raised or hollow pattern at a chosen location on an inner surface of at least one wall of the hollow glass item, thereby superimposing the at least one raised or hollow pattern on the shape of the hollow glass item, removing the punch from the cavity of the mold and stripping the hollow glass item, which includes the at least one inner raised and/or hollow pattern. The punch has a body with an end portion, the end portion has an outer side surface. The body includes a raised or hollow pattern on the outer side surface of the end portion. The raised or hollow pattern is independent of the shape of the hollow glass item. A device for manufacturing a hollow glass item is also provided.