Large field of view head-mounted optical system

Abstract

The large field of view head-mounted optical system comprises an objective optical system, a core module and an eyepiece optical system, the objective optical system and the core module are detachably connected and located on one side of the core module, and the eyepiece optical system is detachably connected on the other side of the core module; the objective optical system comprises a first spherical lens, a second spherical lens, a third spherical lens, a fourth spherical lens, a double-cemented lens and a first aspherical lens arranged in sequence from the object side to the image side along the optical axis direction; the eyepiece optical system comprises a second aspherical lens, a seventh spherical lens and an eighth spherical lens, and the second aspherical lens, the seventh spherical lens and the eighth spherical lens are arranged in sequence from the eye point side to the object side along the optical axis direction. The large field of view head-mounted optical system solves the problem that the large field of view, high imaging quality, small size and light weight cannot be satisfied simultaneously, and can be widely applied in the field of low-light-level night vision or the field of night vision head-mounted.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of digital micro-light night vision equipment and optical elements, and particularly relates to a large-view-field head-mounted optical system. BACKGROUND

[0002] The digital night vision equipment generally takes a low-illumination CCD / CMOS, EBAPS device, etc. as a core component, and combines with an ocular optical system and an objective optical system to realize acquisition and observation of a night vision scene. The digital night vision optical system belongs to a head-mounted optical system, and in order to reduce the head dizziness, it is generally required to be small in size, light in weight, large in field of view and high in imaging quality. The ocular optical system and the objective optical system of the existing digital night vision equipment have a relatively small observation field of view, and generally can only cover a maximum of 45°~50° field of view angle, and the size of the ocular optical system and the objective optical system is relatively large, and the weight is relatively heavy.

[0003] The field of view size and the imaging quality of the night vision ocular optical system and the objective optical system are directly related to the size and the weight thereof. In order to realize high-quality imaging, it is generally required to achieve high resolution and low distortion imaging effect through multi-lens combination design; in order to realize a large field of view of more than 50° while ensuring the imaging quality, long focal length, large aperture and multi-lens combination design are generally required; these will cause the increase of the size and the weight of the ocular optical system and the objective optical system. How to solve the contradiction between the field of view size and the imaging quality and the size and the weight, and realize the ocular optical system and the objective optical system with a large field of view, high imaging quality, small size and light weight is a difficult problem to be broken through at present. SUMMARY

[0004] The purpose of the application is to provide a large-view-field head-mounted optical system, which solves the problems of insufficient large field of view and high imaging quality of the existing night vision ocular optical system and the objective optical system through the combination design of the spherical lens and the aspherical lens.

[0005] The technical scheme adopted by the application is a large-view-field head-mounted optical system, which comprises an objective optical system, a core module and an ocular optical system, the objective optical system and the core module are detachably connected and located on one side of the core module, and the ocular optical system is detachably connected to the other side of the core module.

[0006] The objective optical system comprises, in sequence from the object side to the image side along the optical axis, a first spherical lens, a second spherical lens, a third spherical lens, a fourth spherical lens, a double-cemented lens and a first aspherical lens.

[0007] The ocular optical system comprises a second aspherical lens, a seventh spherical lens and an eighth spherical lens, and the second aspherical lens, the seventh spherical lens and the eighth spherical lens are sequentially arranged from the eye point side to the object side along the optical axis.

[0008] The technical scheme of the application has the following characteristics:

[0009] The first and seventh spherical lenses are meniscus lenses, the second, third, fourth and eighth spherical lenses are convex lenses, and the first and second aspherical lenses are plano-convex lenses.

[0010] The doublet lens comprises a fifth and a sixth spherical lens, the fifth spherical lens is close to the fourth spherical lens, and the fifth and sixth spherical lenses are convex lenses.

[0011] The first spherical lens is made of optical glass H-ZF62, the second and fifth spherical lenses are made of optical glass H-ZF88, the third spherical lens is made of optical glass H-K9L, the fourth spherical lens is made of optical glass H-LAF2, the sixth spherical lens is made of optical glass H-ZLAF52A, and the first aspherical lens is made of optical glass H-ZLAF68C.

[0012] The relative aperture of the objective optical system is between 1:1.4 and 1:1.6, the total length of the objective optical system is not more than 60 mm, the focal length is not more than 15 mm, and the total weight is not more than 45 g;

[0013] The horizontal field of view of the objective optical system is not less than 50°, the vertical field of view is not less than 35°, and the distortion in the overall field of view of the objective optical system is not more than 5%;

[0014] The imaging resolution of the objective optical system is not less than 800 lp / mm, and the clear imaging range is 250 mm to infinity;

[0015] The working waveband of the objective optical system covers visible light to near-infrared.

[0016] The second aspherical lens is made of optical glass H-LA52, the seventh spherical lens is made of optical glass H-ZLAF68C, and the eighth spherical lens is made of optical glass H-ZF88.

[0017] The eye lens optical system has an exit pupil distance of not less than 15 mm and an exit pupil diameter of not less than 4 mm; the focal length of the eye lens optical system is not more than 20 mm, the total length of the eye lens optical system is not more than 30 mm, and the total weight is not more than 50 g;

[0018] The distortion in the overall field of view of the eye lens optical system is not more than 5%;

[0019] The working waveband of the eye lens optical system covers visible light to near-infrared;

[0020] The objective optical system and the eye lens optical system can be used alone or in combination.

[0021] Compared with the prior art, the beneficial effects of the present application are:

[0022] (1) The large field of view head-mounted optical system provided by the present invention is based on general optical glass material. Through the optimized design of spherical lens and aspherical lens combination, it solves the problem that it is difficult to simultaneously meet the requirements of large field of view, high imaging quality and small size and light weight. It can be widely used in the field of low light night vision or night vision head-mounted system. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the large field-of-view head-mounted optical system of the present invention;

[0024] Figure 2 This is a distortion diagram of the objective lens optical system of Embodiment 6 of the present invention;

[0025] Figure 3 This is a blur pattern of the objective lens optical system of Embodiment 6 of the present invention;

[0026] Figure 4 This is an optical transfer function diagram of the objective lens optical system of Embodiment 6 of the present invention;

[0027] Figure 5 This is a distortion diagram of the eyepiece optical system in Embodiment 6 of the present invention;

[0028] Figure 6 This is a diffusion pattern of the eyepiece optical system in Embodiment 6 of the present invention;

[0029] Figure 7 This is the optical transfer function diagram of the eyepiece optical system in Embodiment 6 of the present invention.

[0030] In the figure, 1. First spherical lens, 2. Second spherical lens, 3. Third spherical lens, 4. Fourth spherical lens, 5. Fifth spherical lens, 6. Sixth spherical lens, 7. First aspherical lens, 8. Second aspherical lens, 9. Seventh spherical lens, 10. Eighth spherical lens, 11. Movement module. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] This invention provides a wide field-of-view head-mounted optical system, such as... Figure 1 As shown, it includes an objective lens optical system, a mechanism module 11, and an eyepiece optical system. The objective lens optical system is detachably connected to the mechanism module 11 and is located on one side of the mechanism module 11. The eyepiece optical system is detachably connected to the other side of the mechanism module 11. The objective lens optical system includes a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a fourth spherical lens 4, a cemented doublet lens, and a first aspherical lens 7, which are arranged sequentially from the object side to the image side along the optical axis.

[0033] The double-cemented lens comprises a fifth spherical lens 5 and a sixth spherical lens 6, the fifth spherical lens 5 is close to the fourth spherical lens 4 side, the first spherical lens 1 is a concave-convex lens, the second spherical lens 2, the third spherical lens 3, the fourth spherical lens 4, the fifth spherical lens and the sixth spherical lens are all convex lenses, the first aspherical lens 7 is a flat-convex lens, the core module 11 comprises a shell, the shell is internally provided with a sensor, a processing board and a display screen, the sensor is used for receiving external light collected by the ocular optical system and converting into an electric signal, the processing board is used for analog-digital conversion of the transmitted electric signal and image processing, and the processed image is output to the display screen, and the ocular optical system observes the image on the display screen.

[0034] The first spherical lens 1 is composed of optical glass H-ZF62, the second spherical lens 2 and the fifth spherical lens 5 are composed of optical glass H-ZF88, the third spherical lens 3 is composed of optical glass H-K9L, the fourth spherical lens 4 is composed of optical glass H-LAF2, and the sixth spherical lens 6 is composed of optical glass H-ZLAF52A, and the first aspherical lens 7 is composed of optical glass H-ZLAF68C.

[0035] The relative aperture of the objective optical system is between 1:1.4-1:1.6, the total length of the objective optical system is not more than 60mm, the focal length is not more than 15mm, and the total weight is not more than 45g; the horizontal field of view of the objective optical system is not less than 50°, the vertical field of view is not less than 35°, the distortion in the overall field of view of the objective optical system is not more than 5%; the imaging resolution capability of the objective optical system is not less than 800lp / mm, the clear imaging range is 250mm~infinity; and the working waveband of the objective optical system covers visible light~near infrared.

[0036] The ocular optical system comprises a second aspherical lens 8, a seventh spherical lens 9 and an eighth spherical lens 10, and the second aspherical lens 8, the seventh spherical lens 9 and the eighth spherical lens 10 are sequentially arranged along the optical axis direction from the eye point side to the object side.

[0037] The second aspherical lens 8 is a flat-convex lens, the seventh spherical lens 9 is a concave-convex lens, and the eighth spherical lens 10 is a convex lens; the second aspherical lens 8 is composed of optical glass H-LA52, the seventh spherical lens 9 is composed of optical glass H-ZLAF68C, and the eighth spherical lens 10 is composed of optical glass H-ZF88.

[0038] The exit pupil distance of the ocular optical system is not less than 15mm, and the exit pupil diameter is not less than 4mm; the focal length of the ocular optical system is not more than 20mm, the total length of the ocular optical system is not more than 30mm, and the total weight is not more than 50g. The distortion in the overall field of view of the ocular optical system is not more than 5%. The working waveband of the ocular optical system covers visible~near infrared. The objective optical system and the ocular optical system can be used alone or in combination.

[0039] Embodiment 1

[0040] The embodiment provides a large field of view head-mounted optical system, such as Figure 1 As shown, the head-mounted optical system comprises an objective optical system, a core module 11 and an eyepiece optical system, the objective optical system is detachably connected to one side of the core module 11 and located at the one side of the core module 11, and the eyepiece optical system is detachably connected to the other side of the core module 11; the objective optical system comprises a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a fourth spherical lens 4, a double-cemented lens and a first aspherical lens 7 which are sequentially arranged along the optical axis direction from the object side to the image side; the first spherical lens 1 and the seventh spherical lens 9 are both meniscus lenses, the second spherical lens 2, the third spherical lens 3, the fourth spherical lens 4 and the eighth spherical lens 10 are all convex lenses, and the first aspherical lens 7 and the second aspherical lens 8 are both plano-convex lenses.

[0041] The eyepiece optical system comprises the second aspherical lens 8, the seventh spherical lens 9 and the eighth spherical lens 10, and the second aspherical lens 8, the seventh spherical lens 9 and the eighth spherical lens 10 are sequentially arranged along the optical axis direction from the eye point side to the object side.

[0042] Embodiment 2

[0043] On the basis of the embodiment 1, the double-cemented lens comprises a fifth spherical lens 5 and a sixth spherical lens 6, the fifth spherical lens 5 is close to the fourth spherical lens 4 side, and the fifth spherical lens 5 and the sixth spherical lens 6 are both convex lenses. The core module 1111 comprises a shell, a sensor, a processing board and a display screen are arranged in the shell, the sensor is used for receiving external light collected by the eyepiece optical system and converting the external light into an electric signal, the processing board is used for analog-digital conversion of the transmitted electric signal and image processing, the processed image is output to the display screen, and the eyepiece optical system is used for observing the image on the display screen.

[0044] Embodiment 3

[0045] On the basis of embodiment 2, the first spherical lens 1 is composed of optical glass H-ZF62, the second spherical lens 2 and the fifth spherical lens 5 are composed of optical glass H-ZF88, the third spherical lens 3 is composed of optical glass H-K9L, the fourth spherical lens 4 is composed of optical glass H-LAF2, the sixth spherical lens 6 is composed of optical glass H-ZLAF52A, and the first aspherical lens 7 is composed of optical glass H-ZLAF68C. The relative aperture of the objective optical system is between 1:1.4-1:1.6, the total length of the objective optical system is not more than 60mm, the focal length is not more than 15mm, and the total weight is not more than 45g; the horizontal field of view of the objective optical system is not less than 50°, the vertical field of view is not less than 35°, and the distortion in the overall field of view of the objective optical system is not more than 5%; the imaging resolution capability of the objective optical system is not less than 800lp / mm, the clear imaging range is 250mm~infinity, and the working waveband of the objective optical system covers visible light~near infrared.

[0046] Embodiment 4

[0047] The second aspherical lens 8 is composed of optical glass H-LA52, the seventh spherical lens 9 is composed of optical glass H-ZLAF68C, and the eighth spherical lens 10 is composed of optical glass H-ZF88. The exit pupil distance of the eyepiece optical system is not less than 15mm, and the exit pupil diameter is not less than 4mm; the focal length of the eyepiece optical system is not more than 20mm, the total length of the eyepiece optical system is not more than 30mm, the total weight is not more than 50g, the distortion in the overall field of view of the eyepiece optical system is not more than 5%, and the working waveband of the eyepiece optical system covers visible~near infrared.

[0048] Embodiment 5

[0049] On the basis of embodiment 4, the objective optical system and the eyepiece optical system can be used alone or in combination.

[0050] Embodiment 6

[0051] This embodiment provides a large field of view head-mounted optical system, such as Figure 1As shown, the system includes an objective lens optical system, a mechanism module 11, and an eyepiece optical system. The housing of the objective lens optical system is detachably connected to the mechanism module 11 and is located on one side of the mechanism module 11. The housing of the eyepiece optical system is detachably connected to the other side of the mechanism module 11. The housing of the objective lens optical system includes a first spherical lens 1, a second spherical lens 2, a third spherical lens 3, a fourth spherical lens 4, a cemented doublet lens, and a first aspherical lens 7 arranged sequentially from the object side to the image side along the optical axis. The cemented doublet lens includes a fifth spherical lens 5 and a sixth spherical lens 6. The fifth spherical lens 5 is closer to the fourth spherical lens 4. The first spherical lens 1 is a concave-convex lens. The second spherical lens 2, the third spherical lens 3, the fourth spherical lens 4, the fifth spherical lens, and the sixth spherical lens are all convex lenses. The first aspherical lens 7 is a plano-convex lens. The eyepiece optical system housing includes a second aspherical lens 8, a seventh spherical lens 9, and an eighth spherical lens 10. The second aspherical lens 8, the seventh spherical lens 9, and the eighth spherical lens 10 are arranged sequentially from the eye point side to the object side along the optical axis. The second aspherical lens 8 is a plano-convex lens, the seventh spherical lens 9 is a concave-convex lens, and the eighth spherical lens 10 is a convex lens.

[0052] The mechanism module 11 includes a housing, inside which are a sensor, a processing board, and a display screen. The sensor is used to receive external light collected by the objective lens and convert it into an electrical signal. The processing board performs analog-to-digital conversion on the transmitted electrical signal and performs image processing. The processed image is output to the display screen, and the eyepiece observes the image on the display screen.

[0053] The lens material information for the eyepiece optical system and the objective optical system is shown in Table 1. The eyepiece optical system has an exit pupil diameter of 4.5 mm, an exit pupil distance of 20 mm, a total length of 25 mm, and a total weight of 49 g. The objective optical system has a relative aperture of 1 / 1.4, a horizontal field of view of 50°, a vertical field of view of 39°, a total length of 55 mm, and a total weight of 37 g.

[0054] Table 1 Information on Optical Materials for Objective Lenses and Eyepieces

[0055]

[0056] like Figures 2-4 The figures shown are the distortion diagram, blur pattern, and optical transfer function diagram of the objective lens optical system. From... Figure 2 It can be seen that the objective lens optical system exhibits negative distortion, with the overall field-of-view distortion value not exceeding -3%; from Figure 3 It can be seen that the diameter of the blur spot in the objective lens optical system is less than 0.013 mm in both the on-axis and off-axis fields of view, demonstrating high resolution; from Figure 4 It can be seen that when the optical transfer function (MTF) value of the objective lens optical system is 38.5 line pairs, the modulation frequencies in both the meridional and sagittal directions of the entire field of view are greater than 50%.

[0057] like Figures 5-7 The figures shown are the distortion diagram, blur pattern, and optical transfer function diagram of the eyepiece optical system. From... Figure 5 It can be seen that the eyepiece optical system exhibits positive distortion, with the overall field-of-view distortion value being less than 3%; from Figure 6 It can be seen that the diameter of the blur spot in the eyepiece optical system is less than 0.025 mm in both the on-axis and off-axis fields of view, demonstrating high resolution; from Figure 7 It can be seen that when the optical transfer function (MTF) value of the eyepiece optical system is 70 line pairs, the modulation frequencies in both the meridional and sagittal directions of the entire field of view are greater than 10%.

[0058] In summary, the large field-of-view head-mounted optical system of the present invention, based on general-purpose optical glass materials, and through the optimized design of spherical and aspherical lens combinations, can achieve a large field of view of more than 50° horizontally and more than 35° vertically. The total length of the eyepiece and objective lens optical system is no more than 80mm, and the total weight is no more than 90g. It solves the problem of simultaneously achieving a large field of view, high imaging quality, small size, and light weight, and can be widely used in the fields of night vision equipment or head-mounted optical systems.

Claims

1. A head-mounted optical system of large field of view, characterized in that, The objective optical system, the core module (11) and the eyepiece optical system are connected detachably, the objective optical system is located on one side of the core module (11), and the eyepiece optical system is detachably connected to the other side of the core module (11); The objective optical system comprises, in order from the object side to the image side along the optical axis, a first spherical lens (1), a second spherical lens (2), a third spherical lens (3), a fourth spherical lens (4), a doublet lens and a first aspherical lens (7); The eyepiece optical system comprises a second aspherical lens (8), a seventh spherical lens (9) and an eighth spherical lens (10), which are arranged in order from the eye point side to the object side along the optical axis; The first spherical lens (1) and the seventh spherical lens (9) are both concave-convex lenses, the second spherical lens (2), the third spherical lens (3), the fourth spherical lens (4) and the eighth spherical lens (10) are all convex lenses, and the first aspherical lens (7) and the second aspherical lens (8) are both plano-convex lenses; The doublet lens comprises a fifth spherical lens (5) and a sixth spherical lens (6), the fifth spherical lens (5) is close to the fourth spherical lens (4), and the fifth spherical lens (5) and the sixth spherical lens (6) are both convex lenses; The first spherical lens (1) is composed of optical glass H-ZF62, the second spherical lens (2) and the fifth spherical lens (5) are composed of optical glass H-ZF88, the third spherical lens (3) is composed of optical glass H-K9L, the fourth spherical lens (4) is composed of optical glass H-LAF2, the sixth spherical lens (6) is composed of optical glass H-ZLAF52A, and the first aspherical lens (7) is composed of optical glass H-ZLAF68C; The relative aperture of the objective optical system is between 1:1.4 and 1:1.6, the total length of the objective optical system is not more than 60 mm, the focal length is not more than 15 mm, and the total weight is not more than 45 g; The horizontal field of view of the objective optical system is not less than 50°, the vertical field of view is not less than 35°, and the distortion in the overall field of view of the objective optical system is not more than 5%; The imaging resolution capability of the objective optical system is not less than 800 lp / mm, and the clear imaging range is 250 mm to infinity; The working waveband of the objective optical system covers visible light to near-infrared; The second aspherical lens (8) is composed of optical glass H-LA52, the seventh spherical lens (9) is composed of optical glass H-ZLAF68C, and the eighth spherical lens (10) is composed of optical glass H-ZF88; The exit pupil distance of the eyepiece optical system is not less than 15 mm, the exit pupil diameter is not less than 4 mm, the focal length of the eyepiece optical system is not more than 20 mm, the total length of the eyepiece optical system is not more than 30 mm, and the total weight is not more than 50 g; The distortion in the overall field of view of the eyepiece optical system is not more than 5%; The working waveband of the eyepiece optical system covers visible light to near-infrared.

2. The large field of view head-mounted optical system of claim 1, wherein, The objective optical system and the eyepiece optical system can be used individually or in combination.

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