METHOD FOR PRODUCING AN OPTICAL LENS AND OPTICAL LENS PRODUCED BY SAID METHOD

Abstract

A method for producing an optical lens using an injection mold and to an optical lens produced by the method, wherein, in the method, in a first injection molding step, a first partial body is pre-injection molded in a first cavity and subsequently, in an second injection molding step, in a second cavity, a second partial body is injection molded onto the first partial body, wherein the first partial body and the second partial body are injection molded arranged in front of one another along a thickness axis of the optical lens. The method provides that the first partial body is injection molded with a thickness proportion (a) of 60% to 70% of the total thickness of the optical lens, and wherein the second partial body is injection molded with the remaining thickness proportion (b).

Claims

1. A method for producing an optical lens with an injection mold, the method comprising: pre-injecting, in a first injection molding step, a first partial body in a first cavity; and injection molding, in a second injection molding step, in a second cavity, a second partial body onto the first partial body, wherein the first partial body and the second partial body are injection molded arranged in front of one another along a thickness axis of the lens, and wherein the first partial body is injection molded with a thickness portion of 60% to 70% of the total thickness of the optical lens and the second partial body is injection molded with the remaining thickness proportion.

2. The method according to claim 1, wherein the first partial body is injection molded with a thickness proportion of 64% to 68% of the total thickness of the optical lens.

3. The method according to claim 1, wherein a change in the cavity of the injection mold from the first cavity to the second cavity is produced by an exchangeable core insert.

4. The method according to claim 1, wherein a partial section of the cavity is formed with a molding surface having a microstructure which is reproduced on the surface of the first partial body during injection molding.

5. The method according to claim 1, wherein, after the first injection molding step has taken place, a holding pressure of the plasticized plastic compound is maintained for a period of time in the first cavity.

6. The method according to claim 1, wherein the temperature of the injection mold at least in the area of the sections forming the cavities at least during the injection molding steps is set to a value of 95 C. to 105 C.

7. The method according to claim 3, wherein a sprue is arranged relative to the first core insert such that the injected plasticized plastic compound to form the first partial body flows against the first core insert so that a flow body is formed with the first partial body.

8. An optical lens produced by a method according to claim 1, wherein the body of the optical lens is formed by a first partial body with a thickness proportion of 60% to 70% of the total thickness of the optical lens and by a second partial body with the remaining thickness proportion.

9. The optical lens according to claim 8, wherein the body of the optical lens has a thickness of 20 mm to 35 mm and/or that the body of the optical lens has a diameter or a main axis length of 50 mm to 70 mm perpendicular to a thickness axis.

10. The optical lens according to claim 8, wherein the optical lens has a surface with a microstructure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0020] FIG. 1 shows an injection mold for producing an optical lens in a first injection molding step;

[0021] FIG. 2 shows the injection mold according to FIG. 1 in a second injection molding step; and

[0022] FIG. 3 shows an optical lens produced using the injection molding method of the invention.

DETAILED DESCRIPTION

[0023] FIG. 1 shows a schematic view of an injection mold for performing a first injection molding step I by means of a first cavity 10a, which is produced by the mutual closing of a first mold part 17 of the injection mold and a second mold part 18 of the injection mold. Second mold part 18 of the injection mold comprises a first core insert 14a which is exchangeably received in second mold part 18 of the injection mold. The two mold parts 17 and 18 with core insert 14a are movable relative to one another in an axis that corresponds to thickness axis 13 of the lens to be produced.

[0024] Plasticized plastic compound can be injected into first cavity 10a through a sprue 16, so that a first partial body 11 of optical lens 1 can be formed; see FIG. 3 in this regard.

[0025] First mold part 17 of the injection mold has a molding surface 15, and molding surface 15 delimits first cavity 10a on a side opposite core insert 14a. After a sufficient cooling time, mold parts 17 and 18 can be moved apart again, wherein the produced first partial body 11 of optical lens 1 remains in arrangement on first mold part 17.

[0026] Core insert 14a has a curvature protruding into cavity 10a, so that first cavity 10a is configured approximately in the shape of a meniscus, wherein when the plasticized plastic compound flows in through sprue 16, the plastic compound flows laterally against core insert 14a, so that core insert 14a also serves as a flow body for the plastic compound to enable a controlled inflow of the plastic compound into first cavity 10a.

[0027] FIG. 2 shows the injection mold with mold parts 17 and 18 for performing the second injection molding step II. Core insert 14b with a planar surface delimiting cavity 10b is inserted in second mold part 18 of the injection mold in order to form second cavity 10b in front of first cavity 10a, which is already filled with first partial body 11. If the plasticized plastic compound is again injected through a further sprue 16, second cavity 10b fills and the plasticized plastic compound forms a surface connection to the surface of first partial body 11.

[0028] After a cooling time and solidification of the plasticized plastic compound in second cavity 10b, mold parts 17 and 18 with core insert 14b can be moved apart again along thickness axis 13.

[0029] First cavity 10a has a thickness in thickness axis 13 which corresponds to approximately two thirds of the total thickness of the lens, so that the thickness of second cavity 10b has approximately one third of the total thickness of the lens along thickness axis 13.

[0030] FIG. 3 shows the produced optical lens 1 in a simplified side view, and optical lens 1 has a first partial body 11, produced in the injection molding in first cavity 10a, and optical lens 1 has a second partial body 12 which is produced in the injection molding in second cavity 10b. The thickness proportion a of first partial body 11 corresponds to approximately two thirds of the total thickness of lens 1 and the thickness proportion b of second partial body 12 has a value that corresponds to approximately one third of the total thickness of lens 1. On the outwardly curved outer surface of optical lens 1 in the area of first partial body 11, this surface 15 has a microstructure that was formed from a molding surface 15 in first mold part 17 of the injection mold.

[0031] The invention is not limited in its implementation to the preferred exemplary embodiment described above. Rather, a number of variants are conceivable which make use of the described solution in fundamentally different embodiments as well. All features and/or advantages emerging from the claims, the description, or the drawings, including structural details, spatial arrangements, and method steps, can be essential to the invention both alone and in the most diverse combinations.