CN111367044B

CN111367044B - Human-simulated glasses head

Info

Publication number: CN111367044B
Application number: CN201911385482.6A
Authority: CN
Inventors: 王涌天; 张擎天; 刘越
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2019-12-29
Filing date: 2019-12-29
Publication date: 2021-06-08
Anticipated expiration: 2039-12-29
Also published as: CN111367044A

Abstract

The invention provides a human-simulated spectacle head, which comprises a front lens group and a rear lens group, wherein the front lens group is a negative refractive index lens group and consists of a first lens and a second lens; the rear lens group is a positive refractive index lens group and consists of a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The lens accords with the observation habit of human eyes, is low in cost and simple to process, simulates human eyes to observe a virtual scene through the virtual display equipment by utilizing the lens, and can detect the performance of the virtual display equipment.

Description

Human-simulated glasses head

Technical Field

The invention relates to a pair of humanoid eyeglass heads, belonging to the technical field of optical design.

Background

In 2012, Shanzuo Ji et al inspired by the fact that the refractive index of the center of a human crystalline lens is high and the refractive indexes of both ends are low, manufactured a gradient refractive index lens by using a nano polymer film technology, and the structure of the lens is as shown in fig. 1(a), wherein the front surface and the rear surface are both aspheric surfaces, the refractive index distribution of the lens is as shown in fig. 1(b), the curve above shows the gradual change of the refractive index of the lens, the curve below shows the refractive index distribution of the human crystalline lens, and it can be seen that the refractive index change trends of the two are similar. Imaging simulations were then performed by Shanzuo Ji et al using the gradient index lens, with figure 1(c) showing the stipple distribution of the lens and figure 1(d) showing the actual imaging results of the lens.

The prior art has the following defects:

1. the manufacturing technology of the gradient refractive index material is not mature enough, the material cannot be put into practical use at the present stage, and the aspheric surface processing cost is high, which are not favorable for the large-scale use of the gradient refractive index lens.

2. The gradient index lens has very limited imaging quality, and as can be seen from fig. 1(c), the RMS radius of the stipple diagram of the lens reaches 0.021602mm when the field of view is 1 °, which is far from the imaging effect of human eyes.

Simultaneously, when watching scenes in VR, AR with the head-mounted display, because everyone's eyeball size and interpupillary distance are all the same, when the exit pupil diameter isoparametric of head-mounted display does not satisfy the requirement, can influence people's viewing effect.

Disclosure of Invention

In view of this, the present invention is directed to provide a human-simulated eyeglass head, which conforms to the human eye observation habit, has low cost and is simple to process, and the performance of a virtual display device can be detected by using the lens to simulate human eyes to observe a virtual scene through the virtual display device.

The technical scheme for realizing the invention is as follows:

a human-simulated spectacle head comprises a front lens group and a rear lens group, wherein the front lens group is a negative refractive index lens group and consists of a first lens and a second lens; the rear lens group is a positive refractive index lens group and consists of a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens.

Furthermore, the surface types of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all spherical.

Further, f represents the focal length of the lens, f12 represents the focal length of the front lens group, f37 represents the focal length of the rear lens group, and | f12/f | ≦ 3 of 2 ≦ and | f37/f ≦ 1.5 of 0.5 ≦.

Furthermore, f 1-f 7 respectively represent the focal length of each lens, and the absolute value of f1/f is more than or equal to 1 and less than or equal to 2, the absolute value of f2/f is more than or equal to 1.5, the absolute value of f3/f is more than or equal to 2.5 and less than or equal to 4, the absolute value of f4/f is more than or equal to 2 and less than or equal to 3.5, the absolute value of f5/f is more than or equal to 2 and less than or equal to 3, the absolute value of f6/f is more than or equal to 1 and less than or equal to 2, and the absolute value of f7/f is more than or equal to 0.5 and less than or equal to 1.

Furthermore, the abbe numbers of the second lens and the seventh lens of the invention are less than 40, and the abbe numbers of the first lens, the third lens, the fourth lens, the fifth lens and the sixth lens are more than 60.

Further, the F number of the lens is smaller than 2.

Further, the diaphragm of the present invention is placed in front of the first lens, and D represents the diameter of the diaphragm, so that D is more than 8 mm.

Furthermore, the invention takes a diaphragm as a first surface, the serial number of the surface is 1, the serial number of the image surface is 16 by analogy, and the types, the curvature radius, the surface interval, the material, the refractive index and the abbe number of each surface of the lens are shown in the table 1;

TABLE 1 head parameters of anthropomorphic glasses

Advantageous effects

The human-simulated eyeglass head can be used for simulating the process of observing a virtual scene by human eyes through the virtual display equipment, the optical system can be used for testing the performance of the virtual display equipment subsequently, and lenses in the whole system are designed by adopting a glass spherical surface, so that the human-simulated eyeglass head is low in processing cost and small in difficulty and can be produced in a large scale.

The invention relates to a human eye-imitating lens which accords with the human eye observation habit, the whole lens is designed by adopting 7 glass spherical lenses, a diaphragm is arranged in front of the first surface of the lens, the diameter of the entrance pupil of the system is 10mm and is approximately equal to the maximum aperture which can be reached by the pupil of the human eye, the effective focal length of the system is 19.16mm, the F number is 1.916, the half field angle of the system is 25 degrees, and the system has better MTF within the field range of +/-20 degrees, which is consistent with the central area with higher human eye resolution.

Drawings

FIG. 1(a) is a prior art gradient index human eye lens;

FIG. 1(b) is a refractive index profile of the lens of FIG. 1 (a);

FIG. 1(c) is a dot-sequence diagram of the lens image of FIG. 1 (a);

FIG. 1(d) shows the actual imaging effect of the lens of FIG. 1 (a);

FIG. 2 is a schematic view of a lens structure according to the present invention;

FIG. 3 is a distribution of a dot-sequence diagram of the lens;

fig. 4 shows MTF curve distribution in a 40 ° field of view (full field angle) of the lens.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

The human-simulated spectacle head comprises a front lens group and a rear lens group, wherein the front lens group is a negative refractive index lens group and consists of a first lens (a positive lens) and a second lens (a negative lens); the rear lens group is a positive refractive index lens group and is composed of a third lens (positive lens), a fourth lens (positive lens), a fifth lens (positive lens), a sixth lens (positive lens) and a seventh lens (negative lens). The surface types of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all spherical. The human-simulated eyeglass head conforms to the human eye observation habit, is low in cost and simple to process, so that the system can be used for simulating the process that human eyes observe a virtual scene through the virtual display equipment, and the performance of the virtual display equipment is detected.

In the present embodiment, f denotes a focal length of the lens, f12 denotes a focal length of the front lens group (a combined focal length of the first lens 1 and the second lens 2), f37 denotes a focal length of the rear lens group (a combined focal length of the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, and the seventh lens 7), and | f12/f | ≦ 3 is 2 ≦ and | f37/f | ≦ 1.5. Furthermore, if f 1-f 7 respectively represent the focal length of each lens, the invention has | f1/f ≦ 2 of 1 ≦ f, | f2/f ≦ 1.5 of 1 ≦ f2/f ≦ 4 of 2.5 ≦ f3/f ≦ 4, | f4/f ≦ 3.5 of 2 ≦ f5/f ≦ 3, | f6/f ≦ 2 of 1 ≦ f, and | f7/f ≦ 0.5.

In this embodiment, abbe numbers of the second lens and the seventh lens are less than 40, and abbe numbers of the first lens, the third lens, the fourth lens, the fifth lens and the sixth lens are greater than 60. The F-number of the lens is less than 2. A stop is placed in front of the first lens, and if D represents the diameter of the stop, D is more than 8 mm.

The lens structure of this embodiment is shown in fig. 2, in which the numbers 1 to 7 represent 7 glass lenses, respectively, the number 8 represents the image plane, and the diaphragm is located in front of the lens 1, and the diameter of the diaphragm is 10 mm. The wavelengths adopted during design are 486.1mm, 546.1mm, 587.6mm and 656.3mm, the full field angle is 50 degrees, the effective focal length of the whole system is 19.16mm, and the F number is 1.916. By normalizing the parameters of the lens shown in fig. 2, the normalized effective focal length f' of the lens is 1mm, and the angle of view is 2 ω 50 °. The diaphragm is used as the first surface, the surface serial number is 1, the analogy is carried out, the image surface serial number is 16, the surface types and the surface curvature radiuses of the lens are shown in table 1, the virtual glass is converted into the real glass which is common in the market in the final stage of design, and the system which is converted into the real glass is also used as an evaluation object in the subsequent point list graph and the MTF graph.

TABLE 1 head parameters of anthropomorphic glasses

FIG. 3 is a distribution of stippling of the lens, with an RMS radius of only 0.012919mm at 20 deg. field of view, which is much smaller than the prior art gradient index lens RMS radius (0.021602mm) at 1 deg. field of view. Fig. 4 shows the MTF curve distribution in the 40 ° field of view (full field angle) of the lens, where the frequency range in the graph is 0 to 120lp/mm, and it can be seen that the MTF of the lens at 120lp/mm can reach more than 0.2 in the 40 ° field of view.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A humanoid spectacle head is characterized by comprising a front lens group and a rear lens group, wherein the front lens group is a negative refractive index lens group and consists of a first lens and a second lens; the rear lens group is a positive refractive index lens group and consists of a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens;

a diaphragm is arranged in front of the first lens, the diameter of the diaphragm is represented by D, and D is more than 8 mm; the diaphragm is used as a first surface, the surface serial number is 1, the analogy is repeated, the image surface serial number is 16, and the types, the curvature radius, the surface interval, the material, the refractive index and the Abbe number of each surface of the lens are shown in the table 1;

TABLE 1 head parameters of anthropomorphic glasses

2. The human-eye-imitating lens according to claim 1, wherein the surface types of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all spherical.

3. The human-like eye lens of claim 1, wherein f represents the focal length of the lens, f12 represents the focal length of the front lens group, and f37 represents the focal length of the rear lens group, such that | f12/f | ≦ 3 is 2 ≦ f37/f ≦ 1.5.

4. The artificial eye lens of claim 1, wherein the focal length of each lens is represented by f 1-f 7, and the focal length is 1. ltoreq. f 1/f.ltoreq.2, 1. ltoreq. f 2/f.ltoreq.1.5, 2.5. ltoreq. f 3/f.ltoreq.4, 2. ltoreq. f 4/f.ltoreq.3.5, 2. ltoreq. f 5/f.ltoreq.3, 1. ltoreq. f 6/f.ltoreq.2, and 0.5. ltoreq. f 7/f.ltoreq.1.5.

5. The human-eye-imitating lens according to claim 1, wherein the abbe numbers of the second lens and the seventh lens are less than 40, and the abbe numbers of the first lens, the third lens, the fourth lens, the fifth lens and the sixth lens are greater than 60.

6. The human eye-like lens of claim 1, wherein the F-number of the lens is less than 2.