TWI733585B - Optical lens, mold for optical lens and manufacturing method thereof - Google Patents

Abstract

An optical lens, mold for optical lens and manufacturing method thereof are provided, wherein the optical lens includes a spiral surface spiraling around an axial direction and an intermediate structure around which the spiral surface spirals, the intermediate structure extends axially relative to a side of the spiral surface, and the spiral surface forms a stepped difference. The structure of the mold and the optical lens are correspondingly complementary. The manufacturing method of the mold includes following steps of: providing a base, the base including a processing surface; processing the processing surface to form the spiral surface, the intermediate structure and the stepped difference of the mold.

Description

Optical lens, optical lens forming mold and manufacturing method thereof

The invention relates to an optical lens, an optical lens forming mold and a manufacturing method thereof.

Optical fiber communication has the advantages of good transmission efficiency, resistance to electromagnetic interference and high stability. Optical fiber can be divided into single-mode fiber and multi-mode fiber according to the transmission method. The diameter of the multi-mode fiber is much larger than the wavelength of the light beam, thus allowing light beams of different wavelengths and phases to be reflected and transmitted along the peripheral wall of the fiber. After long-distance transmission There will be a difference in propagation speed between different modes, resulting in modal dispersion and excessively high luminous flux in the center of the fiber, thereby limiting the transmission distance.

In order to solve the aforementioned problems, a vortex phase plate is generally used to convert the passing light beam into a vortex light beam to prevent the light intensity from being concentrated in the central part of the optical fiber. However, the vortex phase plate is not easy to manufacture, and the conventional optical communication module needs to assemble multiple optical elements to complete the arrangement of the optical path. The slight deviation of the installation position of each optical element greatly affects the transmission path of the optical path, and it is difficult to accurately The location, processing is not easy, and the quality is not uniform, which leads to poor transmission effect.

Therefore, it is necessary to provide a novel and progressive optical lens, an optical lens molding mold and a manufacturing method thereof to solve the above-mentioned problems.

The main purpose of the present invention is to provide an optical lens, an optical lens forming mold and a manufacturing method thereof, which has a simple structure, simple manufacturing process, uniform beam dispersion, good processing precision, and is conducive to miniaturization.

In order to achieve the above-mentioned object, the present invention provides an optical lens, which includes a spiral surface spiraling around an axial direction and an intermediate structure spiraled by the spiral surface. The intermediate structure extends axially toward one side of the spiral surface relative to the spiral surface. The spiral surface circulates to form a first step difference.

In order to achieve the above object, the present invention further provides a molding die for manufacturing the optical lens as described above, which includes a spiral surface spiraling around an axial direction and an intermediate structure spiraled by the spiral surface. The intermediate structure of the molding mold With respect to the spiral surface of the forming mold extending axially toward one side, the spiral surface of the forming mold circulates to form a step difference. The spiral surface, intermediate structure and step difference of the forming mold are respectively the same as the spiral surface of the optical lens , Intermediate structure and step difference are relatively complementary.

In order to achieve the above objective, the present invention further provides a manufacturing method for manufacturing the forming mold as described above, which includes the following steps: providing a base, the base including a processing surface; processing the spiral surface of the molding mold on the processing surface , Intermediate structure and level difference.

1: Optical lens

2: Forming mold

3: matrix

4: Tool

11, 21: Axial

12, 22: spiral surface

13,23: Intermediate structure

131, 231: Zhou Bi

14,24: step difference

15,25: arc guide surface

31: Machining surface

32: Axial

41, 42: arc angle

P1: Reference plane

P2: Datum plane

S: Cutting path

T1, T2, T3, T4: Tangent direction

θ 1, θ 4: tilt angle

θ 2, θ 5: the first included angle

θ 3, θ 6: second included angle

Fig. 1 is a perspective view of a forming mold according to a preferred embodiment of the present invention.

Fig. 2 is a partial enlarged view of a forming mold according to a preferred embodiment of the present invention.

Fig. 3 is a schematic diagram of a cutting tool according to a preferred embodiment of the present invention.

Fig. 4 is a partial enlarged view of a cutting tool according to a preferred embodiment of the present invention.

Fig. 5 is a schematic diagram of manufacturing the forming mold according to a preferred embodiment of the present invention.

Fig. 6 is a schematic diagram of an optical lens according to a preferred embodiment of the present invention.

Fig. 7 is a partial enlarged view of an optical lens according to a preferred embodiment of the present invention.

FIG. 8 is a schematic diagram of the effect of uniformly dispersing the vortex of the light beam generated by the optical lens of a preferred embodiment of the present invention.

The following examples are only used to illustrate the possible implementation aspects of the present invention, but they are not intended to limit the scope of protection of the present invention.

Please refer to Figures 1 to 5, which show a preferred embodiment of the present invention for manufacturing the optical lens forming mold 2 as described below, which includes a spiral surface 22 spiral around an axial direction 21 and a spiral The intermediate structure 23 that the surface 22 revolves around. The intermediate structure 23 of the forming mold 2 extends axially toward one side relative to the spiral surface 22 of the forming mold 2, and the spiral surface 22 of the forming mold 2 circulates to form a step 24 .

In this embodiment, the intermediate structure 23 of the forming mold 2 is a convex column, and the diameter of the end surface of the convex column is greater than or equal to 0.001 mm and less than or equal to 0.02 mm; the intermediate structure 23 of the forming mold 2 and the forming mold 2 There is an arc guide surface 25 between the spiral surfaces 22. The arc radius of the arc guide surface 25 of the forming mold 2 is greater than or equal to 0.001mm and less than or equal to 0.02mm; the step difference 24 of the forming mold 2 is greater than or equal to 5μm and less than It is equal to 20μm; the intermediate structure 23 of the forming mold 2 includes a peripheral wall 231, and the peripheral wall 231 of the forming mold 2 forms an inclination angle θ 4 greater than or equal to 1 degree and less than or equal to 20 degrees with respect to the axial direction 21 of the forming mold 2; definition A reference plane P2 perpendicular to the axial direction 21 of the forming mold 2, a tangential direction T3 of an outer edge of the arc guide surface 25 of the forming mold 2 and the reference plane P2 define a first included angle θ5, the forming mold 2 The tangential direction T4 of an outer edge of the spiral surface 22 and the reference plane P2 define a second included angle θ6, and the forming mold The first included angle θ 5 of 2 is greater than the second included angle θ 6 of the molding die 2, the first included angle θ 5 of the molding die 2 is not less than 17.0 degrees, and the second included angle θ 6 of the molding die 2 is not less than 0.70 degrees. Preferably, the first included angle θ 5 is about 17.2 degrees, and the second included angle θ 6 is about 0.72 degrees.

Please refer to FIGS. 6-7, which show an optical lens 1 of a preferred embodiment of the present invention, which includes a spiral surface 12 spiraling around an axis 11 and an intermediate structure 13 spiraled by the spiral surface 12. The structure 13 extends axially toward one side of the spiral surface 12, and the spiral surface 12 circulates to form a step 14. Wherein, the spiral surface 22, the intermediate structure 23, and the step difference 24 of the molding die 2 are relatively complementary to the spiral surface 12, the intermediate structure 13 and the step difference 14 of the optical lens 1, respectively.

In this embodiment, the intermediate structure 13 is a concave hole (blind hole or perforation), and the diameter of the bottom edge of the concave hole is greater than or equal to 0.001 mm and less than or equal to 0.02 mm; the intermediate structure 13 and the spiral surface 12 There is an arc guide surface 15 therebetween. The arc radius of the arc guide surface 15 is greater than or equal to 0.001 mm and less than or equal to 0.02 mm; the step 14 is greater than or equal to 5 micrometers (μm) and less than or equal to 20 μm; the intermediate structure 13 includes A peripheral wall 131, the peripheral wall 131 forms an inclination angle θ 1 with respect to the axial direction 11 of the optical lens 1, the peripheral wall 131 axially exceeds the step 14, and the inclination angle θ 1 is greater than or equal to 1 degree and less than or equal to 20 degrees ; Define a reference plane P1 perpendicular to the axis 11 of the optical lens 1, the tangential direction T1 of an outer edge of the arc guide surface 15 and the reference plane P1 define a first included angle θ 2, one of the spiral surfaces 12 The tangent direction T2 of the outer edge and the reference plane P1 define a second included angle θ 3, the first included angle θ 2 is greater than the second included angle θ 3, the first included angle θ 2 is not less than 17.0 degrees, and the second included angle θ 3 Not less than 0.70 degrees, preferably, the first included angle θ 2 is about 17.2 degrees, and the second included angle θ 3 is about 0.72 degrees.

The optical lens 1 and the molding die 2 are complementary in structure. For example, the intermediate structure 13 of the optical lens 1 is a concave hole, and the intermediate structure 23 of the molding mold 2 is a convex column. It is understandable that if the intermediate structure 13 of the optical lens 1 is a convex column, the molding The middle structure 23 of the mold 2 is a concave hole.

Please refer to FIGS. 1 to 5 again. The present invention also provides a manufacturing method for manufacturing the forming mold 2 as described above, which includes the following steps: a base 3 is provided, and the base 3 includes a processing surface 31; The spiral surface 22, the intermediate structure 23 and the level difference 24 of the forming mold 2 are formed by processing. According to different requirements, a plurality of molding cavities can be formed on the substrate 3, which can be used to manufacture multiple optical lenses at one time. Preferably, a gap between any two adjacent molding cavities is less than or equal to 0.01 mm, so that the vortex beams of the manufactured optical lenses do not interfere with each other.

In this embodiment, a tool 4 is used to cut the processing surface 31 to form the spiral surface 22, the intermediate structure 23, and the step 24 of the forming mold 2. The cutting path S of the tool 4 relative to the base 3 is a spiral The ground is around one axis 32 of the base 3. During cutting, the tool 4 can be fixed and the base 3 can be rotated, or the base 3 can be fixed and the tool 4 can be rotated, or the tool 4 and the base 3 can rotate simultaneously, as long as they can follow the preset cutting path S The machined surface 31 can be cut. In detail, each cutting path S of the tool 4 starts from a relatively high position of the base body 3 from shallow and deep around the axis of the base body 3, and then extends from a relatively low position of the base body 3 back to the relatively high position of the base body 3. . The cutter 4 cuts the processing surface 31 spirally around the axis of the base 3 from outside to inside (or from inside to outside). Among them, the cutting tool 4 is selected with cutting edges having different arc angles 41, 42 on two opposite sides, and the processing surface 31 is cut in such a manner that the cutting edge of the cutting tool 4 has a relatively small arc angle 41 facing inward. Preferably, the arc angles 41, 42 on both sides of the cutting edge of the selected tool 4 respectively have an arc angle radius of less than or equal to 1 μm and an arc angle radius of greater than 1 μm and less than or equal to 5 μm.

In addition, it should be noted that the scale conditions of the above structures are conducive to the uniform dispersion of the vortex of the beam, and also allow processing under the best precision conditions (for example, the use of diamond tools) for molding the optical lens mold, making the mold easy It is processed and manufactured smoothly (due to the inclination angle). In an embodiment of processing the mold for molding the optical lens with a diamond tool, considering that there is a processing limit when processing close to the center of the mold, the side of the diamond tool near the center of the mold is constructed to have a higher The small arc angle radius of the cutting edge on the opposite side can reduce the natural arc angle radius produced by machining to less than 1μm, which is beneficial to machining precision and product miniaturization. The cavity of the mold is formed by laser processing, for example, but it can also be formed by other processing methods.

Please refer to FIG. 8, which shows the uniform vortex dispersion effect of the light beam generated by the optical lens of the present invention. Figure 8 clearly shows that due to the function of the spiral surface of the optical lens, the light is uniformly dispersed spirally, and due to the intermediate structure of the optical lens (such as concave holes or convex pillars), the light is evenly dispersed around the middle At the periphery of the structure, the beam can be prevented from being excessively concentrated in the central part, effectively solving the problem of modal dispersion and excessive luminous flux in the center of the fiber, which limits the transmission distance. Among them, different optical effects can be obtained through various numerical combinations of the diameter of the vortex lens, the angle of the spiral surface, the size of the intermediate structure, and the size of the step difference.

1: Optical lens

11: Axial

12: Spiral

13: Intermediate structure

131: Zhou wall

14: step difference

15: Arc guide surface

P1: Reference plane

T1, T2: Tangent direction

θ 1: Tilt angle

θ 2: The first included angle

θ 3: The second included angle

Claims (20)

An optical lens comprising a spiral surface spiraling around an axial direction and an intermediate structure spiraled by the spiral surface. The intermediate structure extends axially toward one side of the spiral surface relative to the spiral surface, and the spiral surface circulates to form a step However, the intermediate structure includes a peripheral wall, the peripheral wall forms an oblique angle with respect to the axial direction of the optical lens, and the peripheral wall axially exceeds the step. The optical lens according to claim 1, wherein the intermediate structure is a concave hole, and the diameter of the bottom edge of the hole is greater than or equal to 0.001 mm and less than or equal to 0.02 mm. The optical lens according to claim 1, wherein there is an arc guide surface between the intermediate structure and the spiral surface, and the arc radius of the arc guide surface is greater than or equal to 0.001 mm and less than or equal to 0.02 mm. The optical lens according to claim 1, wherein the step difference is 5 micrometers (μm) or more and 20 μm or less. The optical lens according to claim 1, wherein the inclination angle is greater than or equal to 1 degree and less than or equal to 20 degrees. The optical lens according to claim 3, wherein a reference plane perpendicular to the axial direction of the optical lens is defined, a tangent direction of an outer edge of the arc guide surface and the reference plane define a first angle, and the spiral surface The tangent direction of an outer edge and the reference plane define a second included angle, and the first included angle is greater than the second included angle. The optical lens according to claim 6, wherein the first included angle is not less than 17.0 degrees, and the second included angle is not less than 0.70 degrees. A molding die for manufacturing the optical lens according to any one of claims 1 to 7, comprising a spiral surface spiraling around an axial direction and an intermediate structure spiraled by the spiral surface, and the intermediate structure of the molding mold is opposite to The helical surface of the forming mold extends axially toward one side of the forming mold. The spiral surface revolves to form a first step difference, and the spiral surface, intermediate structure and step difference of the molding die are relatively complementary to the spiral surface, intermediate structure and step difference of the optical lens, respectively. The molding die according to claim 8, wherein the intermediate structure of the molding die is a convex column, and the diameter of the end surface of the convex column is greater than or equal to 0.001 mm and less than or equal to 0.02 mm. The forming mold according to claim 8, wherein there is an arc guide surface between the intermediate structure of the forming mold and the spiral surface of the forming mold, and the arc radius of the arc guide surface of the forming mold is greater than or equal to 0.001 mm and less than or equal to 0.02mm. The molding die according to claim 8, wherein the step difference of the molding die is 5 μm or more and 20 μm or less. The molding die according to claim 8, wherein the intermediate structure of the molding die includes a peripheral wall, and the peripheral wall of the molding die forms an inclination angle greater than or equal to 1 degree and less than or equal to 20 degrees with respect to the axial direction of the molding die. The forming mold according to claim 10, wherein a reference plane perpendicular to the axial direction of the forming mold is defined, the tangent direction of an outer edge of the arc guide surface of the forming mold and the reference plane define a first included angle, the The tangent direction of an outer edge of the spiral surface of the forming mold defines a second included angle with the reference plane, and the first included angle of the forming mold is greater than the second included angle of the forming mold. The molding die according to claim 13, wherein the first included angle of the molding die is not less than 17.0 degrees, and the second included angle of the molding die is not less than 0.70 degrees. A manufacturing method for manufacturing the forming mold according to claim 8, comprising the following steps: providing a base, the base including a processing surface; processing the spiral surface, intermediate structure and step difference of the forming mold on the processing surface . The manufacturing method according to claim 15, wherein a tool is used to cut the machined surface to form the spiral surface, intermediate structure and step difference of the forming mold, and the cutting path of the tool on the substrate is spirally around the substrate One axial. The manufacturing method according to claim 16, wherein each cutting path of the tool cuts the machined surface spirally from the outside to the inside around the axis of the substrate. The manufacturing method according to claim 16, wherein a tool whose cutting edge has different arc angles on two opposite sides is selected, and the processing surface is cut in a configuration in which the cutting edge of the tool has a relatively small arc angle and one side faces inward. The manufacturing method according to claim 18, wherein the arc angles on both sides of the cutting edge of the selected tool respectively have an arc angle radius of less than or equal to 1 μm and an arc angle radius of greater than 1 μm and less than or equal to 5 μm. The manufacturing method according to claim 16, wherein each cutting path of the tool is from a relatively high position of the base body from shallow to deep around the axis of the base body, and then extends from a relatively low position of the base body back to the base body Relatively high.

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