CN115793204B

CN115793204B - Six-piece-type micro fish-eye lens

Info

Publication number: CN115793204B
Application number: CN202211414727.5A
Authority: CN
Inventors: 陈俊宏
Original assignee: Hubei Huaxin Photoelectric Co ltd
Current assignee: Hubei Huaxin Photoelectric Co ltd
Priority date: 2022-11-11
Filing date: 2022-11-11
Publication date: 2023-09-01
Anticipated expiration: 2042-11-11
Also published as: CN115793204A

Abstract

The invention provides a six-piece-type micro fish-eye lens, which comprises a first lens, a second lens, a third lens, an aperture diaphragm, a fourth lens, a fifth lens and a sixth lens, wherein the first lens, the second lens, the third lens, the aperture diaphragm, the fourth lens, the fifth lens and the sixth lens are arranged from an object space to an image space along an optical axis, the first lens is a negative lens, and the surface facing the object space is a convex surface and the surface facing the image space is a concave surface; the second lens is a negative lens and is a biconcave mirror surface; the third lens is a negative lens, and the surface facing the object space is a concave surface and the surface facing the image space is a convex surface; the fourth lens is a positive lens and is a biconvex lens; the fifth lens is a negative lens and is a biconcave mirror surface; the sixth lens is a positive lens, and the object-side surface is convex, and the image has the change from convex to concave from the center convex to the edge. The microminiature fisheye lens designed by the invention has small volume, can be suitable for more complex and diversified scenes, and effectively reduces the system cost; the large visual field can increase immersion sense, and a single lens can realize large-scale monitoring.

Description

Six-piece-type micro fish-eye lens

Technical Field

The invention relates to the field of optical devices, in particular to a microminiature fisheye lens with a six-piece structure.

Background

Since 2021, the metauniverse system has rapidly developed, and in the epidemic year, home isolation exposes many living inconveniences, and the metauniverse can perfectly solve the problems. Home office, driving simulation, online teaching, virtual shopping and the like can be realized through meta universe slackening, and the optical lens plays an important pivot role. The meta universe is realized, and visual experience can be brought to users most, so that the visual effect is achieved. Techniques such as AR, VR, etc., in VR optics, a 90 ° field angle is considered to be the sum of the ruled lines of the VR immersion experience, and a 120 ° field angle is generally considered to be the criterion for the partial immersion experience.

Disclosure of Invention

To reduce the mounting size of a lens so as to be usable under various devices; the invention provides a six-piece-type micro fish-eye lens which meets the design requirements of clear imaging and relatively small distortion influence, and consists of a first lens, a second lens, a third lens, an aperture diaphragm, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis, wherein the first lens is a negative lens, and the surface facing the object side is a convex surface and the surface facing the image side is a concave surface; the second lens is a negative lens and is a biconcave mirror surface; the third lens is a positive lens, and the surface facing the object space is a convex surface facing the image space; the fourth lens is a positive lens and is a biconvex lens surface; the fifth lens is a negative lens and is a biconcave mirror surface; the sixth lens is a positive lens, the surface facing the object is a convex surface, and the center convex surface changes from convex to concave in the aspect of image.

On the basis of the technical scheme, the invention can also make the following improvements.

Optionally, the focal length of the fifth lens is f5, and the total focal length of the lens is f1, which satisfies the condition:

1.35≤|f5/f|≤1.75。

optionally, the composite focal length of the first lens (G1), the second lens (L2) and the third lens (L3) is a front group focal length f123, the composite focal length of the fourth lens (L4), the fifth lens (L5) and the sixth lens (L6) is a back group focal length f456, which satisfies the following conditions:

0.6≤f123/f456≤0.75。

optionally, the front group focal length f123 and the total focal length f of the lens satisfy the condition:

2.3≤f123/f≤2.60。

optionally, the back group focal length f456 and the total focal length f of the lens satisfy the condition:

3.3≤f456/f≤3.7。

optionally, the abbe number of the fifth lens is vd5, the curvature radius of the concave surface of the fifth lens is L5R2, wherein:

15≤vd5≤30；

1.4≤|L5R2/f|≤1.8。

the six-piece-type miniature fish-eye lens provided by the invention has small volume, can be suitable for more complex and various scenes, and effectively reduces the system cost; the large visual field can increase immersion sense, and a single lens can realize large-scale monitoring.

Drawings

Fig. 1 is a schematic structural diagram of a six-piece micro fisheye lens according to a first embodiment of the present invention;

fig. 2 is a graph showing the variation of MTF with different frequencies for the micro-miniature fisheye lens of the first embodiment under the same field of view;

FIG. 3 is a graph showing the variation of MTF with field of view at the same frequency for the micro-miniature fisheye lens of the first embodiment;

fig. 4 is a graph showing curvature of field and distortion of a micro fish-eye lens of the first embodiment;

fig. 5 is a ray fan diagram of the micro fish-eye lens of the first embodiment;

FIG. 6 is a diagram showing the relative illuminance of the first embodiment;

fig. 7 is a schematic structural diagram of a six-piece micro fisheye lens according to a second embodiment of the present invention;

fig. 8 is a graph showing the variation of MTF with different frequencies for a micro-miniature fisheye lens of the second embodiment under the same field of view;

fig. 9 is a graph of MTF versus field of view for a second embodiment of a miniature fisheye lens at the same frequency;

fig. 10 is a graph showing curvature of field and distortion of a micro fish-eye lens of the second embodiment;

fig. 11 is a ray fan diagram of a micro-miniature fisheye lens of the second embodiment;

FIG. 12 is a diagram showing the relative illuminance of the second embodiment;

fig. 13 is a schematic structural diagram of a six-piece micro fisheye lens according to a third embodiment of the present invention;

fig. 14 is a graph showing the variation of MTF with different frequencies for a micro-miniature fisheye lens of the third embodiment under the same field of view;

fig. 15 is a graph showing the variation of MTF with field of view at the same frequency for a miniature fisheye lens of the third embodiment;

fig. 16 is a graph of curvature of field and distortion of a miniature fish-eye lens of a third embodiment;

fig. 17 is a ray fan diagram of a micro-miniature fisheye lens of the third embodiment;

FIG. 18 is a diagram showing the relative illuminance of the third embodiment;

fig. 19 is a schematic structural diagram of a six-piece micro fisheye lens according to a fourth embodiment of the invention;

fig. 20 is a graph showing the variation of MTF with different frequencies for a micro-miniature fisheye lens of the fourth embodiment under the same field of view;

fig. 21 is a graph of MTF versus field of view for a miniature fisheye lens of the fourth embodiment at the same frequency;

fig. 22 is a graph of curvature of field and distortion of a miniature fish-eye lens of a fourth embodiment;

fig. 23 is a ray fan diagram of a micro-miniature fisheye lens of the fourth embodiment;

fig. 24 is a diagram showing the relative illuminance of the fourth embodiment.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. In addition, the technical features of each embodiment or the single embodiment provided by the invention can be combined with each other at will to form a feasible technical scheme, and the combination is not limited by the sequence of steps and/or the structural composition mode, but is necessarily based on the fact that a person of ordinary skill in the art can realize the combination, and when the technical scheme is contradictory or can not realize, the combination of the technical scheme is not considered to exist and is not within the protection scope of the invention claimed.

Fig. 1 is a micro-miniature fisheye lens with a six-piece structure according to a first embodiment of the present invention, wherein the micro-miniature fisheye lens is composed of a first lens (G1), a second lens (L2), a third lens (L3), an aperture STOP (STOP), a fourth lens (L4), a fifth lens (L5) and a sixth lens (L6) from an object side to an image side along an optical axis, the first lens (G1) is a negative lens, and a surface facing the object side is a convex surface and a surface facing the image side is a concave surface; the second lens (L2) is a negative lens and is a biconcave mirror; the third lens (L3) is a positive lens, and the surface facing the object space is a convex surface and the surface facing the image space is a convex surface; the fourth lens (L4) is a positive lens and is a biconvex mirror surface; the fifth lens (L5) is a negative lens and is a biconcave mirror; the sixth lens (L6) is a positive lens, and the object-side surface is convex, and the image has a change from convex to concave in the center convex to concave in the edge.

The focal length of the fifth lens is f5, the total focal length of the lens is f1, and the conditions are satisfied: the ratio of f5/f is more than or equal to 1.35 and less than or equal to 1.75.

The synthetic focal length of the first lens (L1), the second lens (L2) and the third lens (L3) is a front group focal length f123, the synthetic focal length of the fourth lens (L4), the fifth lens (L5) and the sixth lens (L6) is a back group focal length f456, and the conditions are satisfied: f123/f456 is more than or equal to 0.6 and less than or equal to 0.75.

The front group focal length f123 and the total focal length f of the lens satisfy the condition: f123/f is less than or equal to 2.3 and less than or equal to 2.60.

The back group focal length f456 and the total focal length f of the lens satisfy the condition: f456/f is more than or equal to 3.3 and less than or equal to 3.7.

The abbe number of the fifth lens is vd5, the curvature radius of the concave surface of the fifth lens is L5R2, wherein: vd5 is more than or equal to 15 and less than or equal to 30; L5R2/f is more than or equal to 1.4 and less than or equal to 1.8.

The microminiature fisheye lens with the six-piece structure has small volume, can be suitable for more complex and diversified scenes, and effectively reduces the system cost; the immersion sense can be increased by a large visual field, and the large-scale monitoring can be realized by a single lens; the front group focal length f 123/total focal length f is more than or equal to 2.3 and less than or equal to 2.60, which is beneficial to lens correction of distortion; the back group focal length f 456/total focal length f is more than or equal to 3.3 and less than or equal to 3.7, which is beneficial to improving the performance of the lens; the fifth lens focal length f5/f is between 1.35 and 1.75 and the abbe number vd is between 15 and 30, which is advantageous for correcting chromatic aberration by the lens.

Among them, tables 1 and 2 are conditions that each lens data and each parameter physical quantity of the micro fish-eye lens of the first embodiment satisfy.

TABLE 1

TABLE 2

Fig. 2 is a graph showing the variation of MTF with different frequencies for the micro-miniature fisheye lens of the first embodiment under the same field of view, wherein the smoother the curve, the better the concentration of T and S.

Fig. 3 is a graph showing the variation of MTF with field of view at the same frequency, with the curves being more concentrated.

Fig. 4 is a graph of curvature of field and distortion of a micro fish-eye lens according to a first embodiment, wherein the left graph is a curvature of field, and reflects the offset of each field of view of the upper graph from the center line of view of the center. The right image is distortion, which refers to deformation generated between an actual image plane and an ideal image plane when an object is imaged through a lens. Smaller values indicate more realistic imaging.

Fig. 5 is a ray fan diagram of the micro-miniature fisheye lens of the first embodiment, wherein the ray fan diagram may also be referred to as a vertical axis aberration diagram. The ordinate is EX, EY, in fact Δx, Δy. Is the distance between the intersection of the rays on the image plane and the ideal image point because in ZEMAX the Z-axis is the optical axis. The ratio of the distance between the two end points to the aperture difference, i.e. the slope, can be converted into a field curvature. Thus Δy2- Δy1/(PY 2-PY 1) is proportional to the field curvature. When the maximum aperture is taken, a wide beam field curvature corresponds. When a tangent to the origin is taken, the corresponding is a beamlet curvature. The average value (DeltaY 2-DeltaY 1)/2 of the two endpoints corresponds to coma.

Fig. 6 is a graph of the relative illuminance of the first embodiment, i.e., the ratio of the illuminance of each field to the center illuminance.

Fig. 7 is a micro-fisheye lens with a six-piece structure according to a second embodiment of the present invention, which has the same structure as the first embodiment, and is different in that: the curvature radius, thickness, and material (including type, refractive index, and abbe number) of each lens are different, and table 3 and table 4 are conditions that each lens data and each parameter physical quantity of the micro fish-eye lens of the second embodiment satisfy.

TABLE 3 Table 3

TABLE 4 Table 4

Fig. 8 is a graph showing the variation of MTF with different frequencies for a micro-miniature fisheye lens of the second embodiment under the same field of view. Fig. 9 is a graph of MTF versus field of view for a second embodiment of a miniature fisheye lens at the same frequency. Fig. 10 is a graph of field curvature and distortion of a micro fish-eye lens of the second embodiment, wherein the left graph is field curvature and the right graph is distortion.

Fig. 11 is a light ray fan diagram of the micro-fisheye lens of the second embodiment, and fig. 12 is a relative illuminance diagram of the first embodiment, that is, a ratio of illuminance of each field to center illuminance.

Referring to fig. 13, a six-piece micro fisheye lens according to a third embodiment of the invention has the same structure as the first and second embodiments, and is different in that: the curvature radius, thickness, and material (including type, refractive index, and abbe number) of each lens are different, and table 5 and table 6 are conditions that each lens data and each parameter physical quantity of the micro fish-eye lens of the second embodiment satisfy.

TABLE 5

TABLE 6

f456/f＝	3.5825
		f123/f＝	2.5163
f123/f456＝	0.7024
		F5/f＝	-1.633
\|L5R2/f\|＝	1.621

Fig. 14 is a graph showing the variation of MTF with different frequencies for a micro-miniature fisheye lens of the third embodiment under the same field of view. Fig. 15 is a graph showing the variation of MTF with field of view at the same frequency for the micro-miniature fisheye lens of the third embodiment. Fig. 16 is a graph of field curvature and distortion of a micro fish-eye lens of the third embodiment, wherein the left graph is field curvature and the right graph is distortion.

Fig. 17 is a light ray fan diagram of the micro-fisheye lens of the third embodiment, and fig. 18 is a relative illuminance diagram of the third embodiment, that is, a ratio of illuminance of each field to center illuminance.

Referring to fig. 19, a six-piece micro fisheye lens according to the fourth embodiment has the same structure as the first, second and third embodiments, and is different in that: the curvature radius, thickness, and material (including type, refractive index, and abbe number) of each lens are different, and table 7 and table 8 are conditions that each lens data and each parameter physical quantity of the micro fish-eye lens of the second embodiment satisfy.

TABLE 7

TABLE 8

f456/f＝	3.6110
		f123/f＝	2.4089
f123/f456＝	0.6671
		f5/f＝	-1.5237
\|L5R2/f\|＝	1.5857

Fig. 20 is a graph showing the variation of MTF with different frequencies for a micro-miniature fisheye lens of the fourth embodiment under the same field of view. Fig. 21 is a graph of MTF versus field of view for a miniature fisheye lens of the fourth embodiment at the same frequency. Fig. 22 is a graph of field curvature and distortion of a micro fish-eye lens of the fourth embodiment, wherein the left graph is field curvature and the right graph is distortion.

Fig. 23 is a light ray fan diagram of the micro-fisheye lens of the fourth embodiment, and fig. 24 is a relative illuminance diagram of the fourth embodiment, that is, a ratio of illuminance of each field to center illuminance.

The six-piece-type micro fish-eye lens provided by the embodiment of the invention has the advantages that the designed micro fish-eye lens is small in size, can be suitable for more complex and various scenes, and effectively reduces the system cost; the immersion sense can be increased by a large visual field, and the large-scale monitoring can be realized by a single lens; the front group focal length f 123/total focal length f is more than or equal to 2.3 and less than or equal to 2.60, which is beneficial to lens correction of distortion; the back group focal length f 456/total focal length f is more than or equal to 3.3 and less than or equal to 3.7, which is beneficial to improving the performance of the lens; the fifth lens focal length f5/f is between 1.35 and 1.75 and the abbe number vd is between 15 and 30, which is advantageous for correcting chromatic aberration by the lens.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. The miniature fisheye lens with the six-piece structure is characterized by comprising a first lens, a second lens, a third lens, an aperture diaphragm, a fourth lens, a fifth lens and a sixth lens from an object space to an image space along an optical axis, wherein the first lens is a negative lens, and the surface facing the object space is a convex surface and the surface facing the image space is a concave surface; the second lens is a negative lens and is a biconcave mirror surface; the third lens is a positive lens, and the surface facing the object space is a convex surface facing the image space; the fourth lens is a positive lens and is a biconvex lens surface; the fifth lens is a negative lens and is a biconcave mirror surface; the sixth lens is a positive lens, the surface facing the object space is a convex surface, and the center convex surface changes from convex to concave in the aspect of image;

the synthetic focal length of the first lens (G1), the second lens (L2) and the third lens (L3) is a front group focal length f123, the synthetic focal length of the fourth lens (L4), the fifth lens (L5) and the sixth lens (L6) is a back group focal length f456, and the conditions are satisfied:

0.6≤f123/f456≤0.75。

2. the six-piece micro-fisheye lens according to claim 1, wherein the focal length of the fifth lens is f5, and the total focal length of the lens is f1, which satisfies the condition:

1.35≤|f5/f|≤1.75。

3. the six-piece micro-fisheye lens according to claim 1, wherein the front group focal length f123 and the total lens focal length f satisfy the condition:

2.3≤f123/f≤2.60。

4. the six-piece micro-fisheye lens according to claim 1, wherein the back group focal length f456 and the total focal length f satisfy the condition:

3.3≤f456/f≤3.7。

5. the six-piece structured micro-miniature fisheye lens of claim 1, wherein the abbe number of the fifth lens is vd5, the radius of curvature of the concave surface of the fifth lens is L5R2, wherein:

15≤vd5≤30；

1.4≤|L5R2/f|≤1.8。