US 12,377,585 B2
Method for producing an optical element from plastic
Florian Pilz, Neustadt an der Orla (DE); and Sven Fröhlich, Neustadt an der Orla (DE)
Assigned to DOCTER OPTICS SE, Neustadt an der Orla (DE)
Appl. No. 17/791,002
Filed by Docter Optics SE, Neustadt an der Orla (DE)
PCT Filed Jan. 13, 2021, PCT No. PCT/DE2021/100035
§ 371(c)(1), (2) Date Jul. 6, 2022,
PCT Pub. No. WO2021/143981, PCT Pub. Date Jul. 22, 2021.
Claims priority of application No. 10 2020 100 888.0 (DE), filed on Jan. 15, 2020; and application No. 10 2020 116 793.8 (DE), filed on Jun. 25, 2020.
Prior Publication US 2023/0029379 A1, Jan. 26, 2023
Int. Cl. B29C 45/16 (2006.01); B29L 11/00 (2006.01)
CPC B29C 45/1618 (2013.01) [B29C 45/1679 (2013.01); B29K 2995/0018 (2013.01); B29L 2011/0016 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of producing an optical lens element having at least one optically effective light exit surface and having at least one optically effective light entrance surface, the method comprising:
providing a first injection mold;
providing a second injection mold;
liquefying a transparent plastic;
injecting the liquefied transparent plastic into the first injection mold to form a pre-molded part comprising a sprue, a first preform, and a second preform, wherein the first preform and the second preform are connected via the sprue;
cooling the pre-molded part outside the first injection mold;
placing the pre-molded part in the second injection mold; and
injecting the liquefied transparent plastic into the second injection mold which over-molds the first preform and the second preform to form a first optical lens element and a second optical lens element, respectively, wherein the first optical lens element comprises a first layer that comprises a first optically effective light exit surface and the second optical lens element comprises a second layer that comprises a second optically effective light exit surface, wherein at least 70% of the first layer and at least 70% of the second layer are not thicker than 1 mm;
separating the sprue from the first optical lens element; and
separating the sprue from the second optical lens element.