CN110456480A - A miniaturized high-pixel panoramic day and night confocal optical system - Google Patents

Abstract

The invention discloses a miniaturized high-pixel panoramic day-night confocal optical system, which comprises a front lens group, a diaphragm, a rear lens group and an image plane arranged sequentially from front to back along the incident direction of light. The first lens, the second lens and the third lens are arranged in sequence in the rear, and the rear lens group includes the fourth lens, the fifth lens, the sixth lens and the seventh lens arranged in sequence from front to back. The present invention adopts a drum-shaped thick lens at the front end of the diaphragm to realize the compact design of the optical path, and the length of the optical system is only 20.439 mm, which meets the miniaturization requirements of a high-resolution panoramic camera, realizes high-resolution and high-resolution imaging, and has reasonable focal power distribution , the process can be realized well, and it is easy to realize mass production and assembly.

Description

A miniaturized high-pixel panoramic day and night confocal optical system

technical field

The invention relates to the technical field of optical systems, more specifically to a miniaturized high-pixel panoramic day-night confocal optical system.

Background technique

Due to the large imaging field of view exceeding 360°×180°, the panoramic optical system can obtain scene images without dead angles, which cannot be achieved by general optical systems or lenses. Therefore, the panoramic optical system has been widely used in security, surveillance, AR/VR and other fields. The panoramic optical system pursues super-large field of view, large relative aperture, and high-resolution performance indicators. Most of the existing optical systems suitable for high-resolution panoramic cameras have defects such as relatively complex structures and large sizes.

Contents of the invention

The present invention provides a miniaturized high-pixel panoramic day-night confocal optical system that uses fewer lenses, high imaging resolution, compact structure, and short optical system length, which is beneficial to improving the application level of the panoramic camera optical system.

The solution that the present invention solves its technical problem is:

A miniaturized high-pixel panoramic day and night confocal optical system, including a front lens group, a diaphragm, a rear lens group and an image plane arranged sequentially from front to back along the incident direction of light, and the front lens group includes a first lens, a second lens, and a third lens, the rear lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially from front to back;

The first lens is a meniscus lens with a negative refractive power, the fourth lens and the sixth lens are biconvex lenses with a positive refractive power, and the second lens and the fifth lens are both optical focal lengths A biconcave lens with a negative power, the seventh lens is a meniscus lens with a positive power; the third lens is a drum-shaped thick lens with a positive power, the fourth lens and the fifth lens Form a doublet lens.

As a further improvement of the above technical solution, the optical power of the front lens group is The focal power of the optical system is in and The ratio satisfies:

As a further improvement of the above technical solution, the optical power of the rear lens group is The focal power of the optical system is in and The ratio satisfies:

As a further improvement of the above technical solution, the optical power of the third lens is The focal power of the optical system is in and The ratio satisfies:

As a further improvement of the above technical solution, the optical surface of the third lens close to the diaphragm is the first optical surface, the optical surface of the fourth lens close to the diaphragm is the second optical surface, and the axial view of the optical system is The height value of the field edge ray on the first optical surface is h1, and the height value of the off-axis field edge ray on the second optical surface is h2, wherein h2/h1 satisfies:

1.04≤h1/h2≤1.16.

As a further improvement of the above technical solution, the distance between the diaphragm and the center of the third lens is L1, and the distance between the diaphragm and the center of the fourth lens is L2, wherein the ratio of L1/L2 satisfies:

3.15≤L1/L2≤3.75.

As a further improvement of the above technical solution, the optical power of the first lens is

The focal power of the second lens is The combined refractive power of the fourth lens and the fifth lens is The focal power of the sixth lens is The focal power of the seventh lens is in and Satisfy:

As a further improvement of the above technical solution, the material of the first lens and the sixth lens is heavy lanthanum flint glass, the material of the second lens and the fourth lens is lanthanum crown glass, the third lens and the fifth lens The material of the seventh lens is heavy flint glass, and the material of the seventh lens is heavy crown glass.

As a further improvement of the above technical solution, the first lens, the second lens and the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all spherical glass lenses.

As a further improvement of the above technical solution, a filter is provided between the seventh lens and the image plane.

The beneficial effects of the present invention are: the present invention adopts a drum-shaped thick lens at the front end of the diaphragm to realize the compact design of the optical path, and the length of the optical system is only 20.439mm, which meets the miniaturization requirements of the high-resolution panoramic camera and realizes high-resolution and high-resolution Imaging, optical focal power allocation is reasonable, process can be realized well, and it is easy to realize mass production and assembly.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly describe the drawings that need to be used in the description of the embodiments. Apparently, the described drawings are only some embodiments of the present invention, not all embodiments, and those skilled in the art can obtain other designs and drawings based on these drawings without creative work.

Fig. 1 is the optical system structure schematic diagram in the embodiment;

Fig. 2 is the optical transfer function curve of the visible spectrum segment of the optical system in the embodiment;

Fig. 3 is the optical transfer function curve of the night vision 850nm spectrum section of optical system in the embodiment;

Fig. 4 is a vertical axis chromatic aberration curve of the optical system in the embodiment.

Detailed ways

The concept, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, features and effects of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts belong to The protection scope of the present invention. In addition, all connection relationships mentioned in this article do not refer to the direct connection of components, but mean that a better connection structure can be formed by adding or reducing connection accessories according to specific implementation conditions. The various technical features in the invention can be combined interactively on the premise of not conflicting with each other.

Embodiment 1, referring to FIG. 1 , a miniaturized high-pixel panoramic day-night confocal optical system includes a front lens group 120, a diaphragm 110, a rear lens group 130, and an image surface 800 arranged sequentially from front to back along the incident direction of light. The front lens group 120 includes a first lens 100, a second lens 200, and a third lens 300 arranged in sequence from front to back, and the rear lens group 130 includes a fourth lens 400 and a fifth lens 500 arranged in sequence from front to back. , the sixth lens 600 and the seventh lens 700;

The first lens 100 is a meniscus lens with negative refractive power, the fourth lens 400 and the sixth lens 600 are biconvex lenses with positive refractive power, and the second lens 200 and the fifth lens 500 are biconcave lenses with negative refractive power, the seventh lens 700 is a meniscus lens with positive refractive power; the third lens 300 is a drum-shaped thick lens with positive refractive power, and the The fourth lens 400 and the fifth lens 500 form a doublet lens.

The third lens 300 is a drum-type lens with positive refractive power, and the drum-type lens is a special form of biconvex lens. The diaphragm 110 is an aperture diaphragm.

The optical system of the present invention adopts an anti-telephoto optical structure type. Since the imaging field of view reaches more than 220°, in order to reduce field aberrations such as astigmatism and distortion caused by the super-large field of view, the front lens group 120 adopts two A negative focal power lens can obtain a larger reciprocal value of the chief ray magnification, thereby reducing the pressure of the rear group aberration correction.

The focus of the present invention is to consider the miniaturization and compact design of the optical system under the premise of realizing high image quality, and carry out corresponding innovative design and reasonable aberration correction; when the length of the optical system is shortened, due to the The increase of the focal power will cause various aberrations such as spherical aberration, coma, astigmatism, and distortion to increase rapidly, resulting in a decrease in the image quality of the optical system. In order to realize the compact design of the panoramic optical system, the present invention introduces the third lens 300, which is a drum-type thick lens with positive refractive power, in the front lens group 120; height, and has a greater converging effect on the light, which further reduces the height of the outgoing light and greatly reduces the aberration correction pressure of the rear lens group 130, thereby obtaining high imaging quality while reducing the size of the optical system.

The invention adopts a drum-shaped thick lens at the front end of the diaphragm 110 to realize the compact design of the optical path, and the length of the optical system is only 20.439 mm, which meets the miniaturization requirements of a high-resolution panoramic camera, realizes high-resolution, high-resolution imaging, and focal power distribution It is reasonable, the process can be realized well, and it is easy to realize mass production and assembly.

As a further improvement of the above technical solution, the optical power of the front lens group 120 is The focal power of the optical system is in and The ratio satisfies:

As a preferred embodiment, the optical power of the rear lens group 130 is The focal power of the optical system is in and The ratio satisfies:

As a preferred implementation manner, the refractive power of the third lens 300 is The focal power of the optical system is in and The ratio satisfies:

As a preferred embodiment, the optical surface of the third lens 300 close to the diaphragm 110 is the first optical surface, the optical surface of the fourth lens 400 close to the diaphragm 110 is the second optical surface, and the axis of the optical system The height value of the edge rays of the upper field of view on the first optical surface is h1, and the height value of the edge rays of the off-axis field of view on the second optical surface is h2, wherein h2/h1 satisfies:

1.04≤h1/h2≤1.16.

As a preferred embodiment, the distance between the diaphragm 110 and the center of the third lens 300 is L1, and the distance between the diaphragm 110 and the center of the fourth lens 400 is L2, wherein the ratio of L1/L2 Satisfy:

3.15≤L1/L2≤3.75.

As a preferred embodiment, the refractive power of the first lens 100 is The focal power of the second lens 200 is The combined refractive power of the fourth lens 400 and the fifth lens 500 is The focal power of the sixth lens 600 is The focal power of the seventh lens 700 is in and Satisfy:

In order to meet the application requirements of confocal day and night, the axial chromatic aberration and vertical chromatic aberration of the system are corrected by using a doublet lens with a focal power close to zero, and the near-infrared spectrum of 850nm and the visible spectrum are confocally corrected. Realize day and night confocal dual-use.

As a preferred embodiment, the material of the first lens 100 and the sixth lens 600 is heavy lanthanum flint glass, the material of the second lens 200 and the fourth lens 400 is lanthanum crown glass, and the third lens 300 and The material of the fifth lens 500 is heavy flint glass, and the material of the seventh lens 700 is heavy crown glass.

As a preferred embodiment, the first lens 100 , the second lens 200 , the third lens 300 , the fourth lens 400 , the fifth lens 500 , the sixth lens 600 and the seventh lens 700 are all spherical glass lenses.

All the lenses of the optical system adopt spherical glass lenses, which are easy to process and low in cost.

As a preferred implementation manner, a filter 900 is provided between the seventh lens 700 and the image plane 800 .

The optical filter 900 is used to realize spectral imaging of a specific range, and avoid the entry of other wavelengths of the spectrum, which will affect the imaging quality.

The optical system of the present embodiment, specific parameter is:

The focal length is 1.41mm; the relative aperture D/f is 1/2.2; the field of view is 220°; the total length of the optical system is 20.439mm, and the rear working distance (distance from the seventh lens 700 to the image plane 800) is 3.165mm.

In the embodiment of the present invention, as shown in accompanying drawings 2 and 3, the focal plane position difference between the visible spectrum and the near-infrared spectrum is very small, and the imaging quality of the two spectrums can be satisfied at the same time on the same image plane 800 The average transfer function value of the full field of view at 180lp/mm in the visible spectrum is better than 0.5, and the average transfer function value of the full field of view is close to 0.30 at 360lp/mm; the average transfer function of the full field of view at 180lp/mm in the near infrared 850nm The function value is better than 0.42, and the average transfer function value of the full field of view is better than 0.12 at 360lp/mm. It guarantees high-resolution analytical image quality in different spectral bands, and realizes day and night confocal imaging.

In the embodiment of the present invention, considering that the lighting conditions of the application environment of the panoramic camera are relatively complicated, if the optical system does not correct the purple fringing well, the purple fringing effect will easily appear in the imaging of the scene, which will become an obstacle that affects the clarity of the boundary between the bright and dark scenes of the image. stray light interference. In the embodiment of the present invention, the purple fringing of 435nm is well corrected, as shown in Figure 4, within the full field of view, the 435nm and 656nm spectra are in an overlapping state, and there is no phenomenon that 435nm is far away from other spectra. The purple fringing effect is well avoided.

The optical system of the present invention adopts a drum-shaped thick lens at the front end of the diaphragm 110 to realize a compact design of the optical path, and the length of the optical system is only 20.439mm, which meets the miniaturization requirements of a high-resolution panoramic camera; the average value of the transfer function of the full field of view is close to 0.3@360lp/ mm, the pixel resolution has reached 12 million, realizing high-resolution and high-resolution imaging; the spherical lens design is adopted, the optical focal power distribution is reasonable, the process can be realized well, and it is easy to realize mass production and assembly.

The preferred embodiments of the present invention have been described in detail above, but the invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent modifications or replacements without violating the spirit of the present invention. These equivalent modifications or replacements are all within the scope defined by the claims of the present application.

Claims (10)

1. a kind of high pixel panorama of miniaturization day and night confocal optical system, it is characterised in that: including along light incident direction before Front lens group, diaphragm, rear lens group and the image planes set gradually backward, the front lens group include setting gradually from front to back First lens, the second lens and the third lens, the rear lens group include the 4th lens set gradually from front to back, the 5th thoroughly Mirror, the 6th lens and the 7th lens；

First lens are the meniscus shaped lens that focal power is negative, and the 4th lens and the 6th lens are that focal power is positive Biconvex lens, second lens and the 5th lens are the biconcave lens that focal power is negative, and the 7th lens are light focus Spend the meniscus shaped lens being positive；The third lens are the drum type thick lens that focal power is positive, and the 4th lens and the 5th are thoroughly Microscope group is at cemented doublet.

2. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described The focal power of front lens group isThe focal power of the optical system isWhereinWithRatio meet:

3. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described The focal power of rear lens group isThe focal power of the optical system isWhereinWithRatio meet:

4. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described The focal power of the third lens isThe focal power of the optical system isWhereinWithRatio meet:

5. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described The third lens are the first optical surface close to the optical surface of diaphragm, and the 4th lens are the second optics close to the optical surface of diaphragm Face, field of view edge light is h1 in the height value of first optical surface on the axis of the optical system, the optical system The outer field of view edge light of axis is h2 in the height value of second optical surface, and wherein h2/h1 meets:

1.04≤h1/h2≤1.16。

6. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described Diaphragm is L1 at a distance from the center of the third lens, and the diaphragm is L2 at a distance from the center of the 4th lens, The ratio of middle L1/L2 meets:

3.15≤L1/L2≤3.75。

7. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described First power of lens isSecond power of lens isThe group of 4th lens and the 5th lens Light combination focal power is6th power of lens is7th power of lens isWherein WithMeet:

8. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: described The material of first lens and the 6th lens is attached most importance to lanthanum flint glass, and the material of second lens and the 4th lens is lanthanum crown glass The material of glass, the third lens and the 5th lens is dense flint glass, and the material of the 7th lens is dense crown.

9. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: first Lens, the second lens and the third lens, the 4th lens, the 5th lens, the 6th lens and the 7th lens are spherical glass lens.

10. a kind of high pixel panorama of miniaturization according to claim 1 day and night confocal optical system, it is characterised in that: institute It states and is equipped with optical filter between the 7th lens and image planes.