WO2018000651A1 - Imaging device - Google Patents

Abstract

An imaging device, which comprises two imaging systems having the same structure. Each imaging system must have a wide-angle lens and an image sensor. The two wide-angle lenses both have viewing field angles greater than 180 degrees, and in each wide-angle lens, a front lens assembly (2), an independent reflecting element (12) and a rear lens assembly (3) are arranged successively starting from an object side. The optical axis of the front lens assembly (2) is bent towards the rear lens assembly (3) sequentially via the reflecting element (12). Images captured by the two wide-angle lenses are combined into an image having a solid angle of 4π radian. The separated structure can not only reduce the space from the two lenses to a first piece of lens in a light incident direction, but is also beneficial for assembly and production.

Description

Imaging device Technical field:

The present invention relates to an optical imaging device.

Background technique:

An existing image capture system capable of ingesting a 4π solid angle is implemented using two wide-angle lenses. The more common solution on the market is to use two independent back-to-back wide-angle lenses. The characteristic of this type of scheme is that after the two lenses and the sensor form a module, the optical axes coincide and form an optical system in the opposite direction. Due to the imaging system consisting of two wide-angle lenses, the length of the optical axis direction is superimposed on the total length of each lens. The lens requires a longer length as the resolution of the lens increases or the size of the sensor becomes larger.

When two wide-angle lenses with an angle of more than 180° are combined, there is a non-overlapping portion between the maximum incident angle rays of the two wide-angle lenses. In the future, the "non-overlapping portion" is referred to as "unimageable portion", and it is needless to say that the "non-imageable portion" should be as small as possible. Obviously, such a lens has a larger "unimageable portion" due to its longer length in the optical axis direction.

The Japanese Patent Application Publication No. 2010-271675 and the Chinese Patent Application Publication No. 103685886A can reduce the non-overlapping portions by turning the optical path by the optical path turning device. In order to further reduce the "non-imageable portion", Chinese Patent Application Publication No. 103685886A discloses an image forming apparatus that shares a reflecting device and a common body tube portion, which is referred to as a unitary structure. Although this technique can improve the length of the imaging system in the optical axis direction and shorten the non-overlapping portions, it needs to assemble two wide-angle lenses on one holder. The common reflection device and the main tube portion of the wide-angle lens mean that in production. At the same time, the performance of the two wide-angle lenses is guaranteed, which means that there is a poor lens and the entire imaging device will be bad, which greatly increases the defect rate and uncertainty in production, which is very unfavorable for mass production. With the improvement of sensor technology and the development of image transmission technology, the market demand for pixels of imaging systems is getting higher and higher. When the case corresponds to 4K high pixels, the defective rate of the lens is increased, causing a sudden increase in the defective rate of the imaging system. Therefore, this technique has the disadvantages of complicated assembly, high precision, and high defect rate in the case of corresponding high pixels.

Once the integrated structure is determined, it cannot be changed, and the appearance cannot be adjusted according to customer needs, and the degree of customization is low. The one-piece structure is shortened in the direction of the optical axis, but it is sacrificed perpendicular to the optical axis. The direction of the optical axis is taken as the Z-axis, and when the optical path is turned, a part of the length of each lens is shifted to the X-axis and the Y-axis. The one-piece structure shares the reflecting means such that the turned portion is simultaneously parallel to the X-axis or the Y-axis. Obviously, the length on the X-axis or the Y-axis is increased, that is, the length in a certain direction perpendicular to the optical axis is increased, which is disadvantageous for miniaturization.

Summary of the invention:

The present invention overcomes the above-mentioned shortcomings of the prior art, and provides an image forming apparatus which has high productivity, high yield, variable shape, and high degree of customization in the case of high productivity.

An imaging apparatus of the present invention is composed of two identical first imaging systems and a second imaging system, the two imaging systems having the same imaging structure and being centrally symmetric with each other; the imaging structure including one over 180 a wide-angle lens of the angle of view and a sensor for taking an image formed by the wide-angle lens;

The wide-angle lens includes a front mirror assembly, a reflective member, and a rear mirror assembly, which are arranged from the object side to the image side, and the optical axis of the front mirror assembly is bent toward the rear mirror assembly by the reflection of the reflective member; An imaging system and an image taken by the second imaging system are combined to obtain an image having a solid angle of 4π, which is characterized by:

The first wide-angle lens of the first imaging system and the second wide-angle lens of the second imaging system have separate holders and reflective elements, and the holders are coupled together by a connecting device such that the front lens assembly and the first wide-angle lens The optical axes of the front lens assembly components of the two wide-angle lenses are aligned and the lens arrangement directions are opposite to each other, and the optical axes of the rear mirror assembly of the first wide-angle lens and the rear mirror assembly of the second wide-angle lens are parallel or at an angle to each other.

Further, the cage includes a front tube for mounting the front mirror assembly and a rear tube for mounting the rear mirror assembly, the optical axes of the front and rear tubes being perpendicular to each other; the front and rear tubes a reflective element is disposed in the connecting portion, and the connecting portion is a platform is provided, the platform is parallel to the optical axis of the front tube and perpendicular to the optical axis of the rear tube, and the platform is provided with a circular hole for mounting;

The connecting device for connecting the cage comprises the above-mentioned platform and mounting circular hole, and further comprises a positioning circular hole disposed at the end of the front tube and a positioning cylinder disposed on the side wall of the rear tube, and the positioning cylinder of the cage is inserted into another retaining cylinder In the positioning hole of the frame, the platform of the cage is fitted with the platform of the other cage, so that the mounting holes on the two cages are aligned and the screws are loaded.

Furthermore, the present invention achieves the function of back focus adjustment by adjusting the relative position of the rear mirror assembly components in the cage. The rear mirror assembly moves back and forth along the optical axis in the cage. The rear mirror unit component retainer has not less than a fitting relationship, and the outer side of the rear mirror unit has a ring groove or other iconic design corresponding to the initial position of the cage. After the initial positions are roughly corresponding, the relative position of the rear mirror group components in the cage is adjusted by an external force, and the focusing adjustment is completed according to the actual imaging device effect, and the rear mirror assembly is fixed in the holder.

On the outside of the cage, there is a plane reference for the bearing to determine the vertical extent of the optical axis for a single assembly.

With a separate structure, you only need to ensure the performance of a single wide-angle lens, and a combination of two good lenses can form a good device.

The present invention can enlarge the distance between two wide-angle lenses and rotate one of them around the optical axis of the front lens group by a certain angle.

The invention has the advantages of good productivity, simple assembly, high yield rate, easy adjustment of appearance according to customer demand, high degree of customization, and convenience for miniaturization.

DRAWINGS

Adding a drawing illustrates the uncapable area of the back-to-back system.

Figure 1 is a schematic view showing the structure of the system of the present invention.

2 is a schematic diagram of an MTF of a wide-angle lens example 1.

FIG. 3 is a schematic diagram of axial chromatic aberration of Example 1 of the wide-angle lens.

4 is a schematic diagram of curvature of field of the first example of the wide-angle lens.

FIG. 5 is a schematic diagram of the contrast of the wide-angle lens example 1.

6 is a schematic structural view of a second example of a wide-angle lens

7 is a schematic diagram of field curvature and axial chromatic aberration of the second example of the wide-angle lens.

8 is a schematic structural view of a third example of a wide-angle lens.

9 is a schematic diagram of field curvature and axial chromatic aberration of the third example of the wide-angle lens.

FIG. 10 is a schematic diagram of the 180 degree state mechanism of the optical axis of the back mirror group of the wide-angle lens example.

11 is a schematic diagram of the 0 degree state of the optical axis of the rear mirror assembly of the wide-angle lens example.

FIG. 12 is a schematic diagram showing the 90 degree state of the optical axis of the rear mirror assembly of the wide-angle lens example.

Figure 13 is a schematic diagram of the 135 degree state of the optical axis of the rear mirror assembly of the wide-angle lens example.

14 is a schematic view showing the structure of a frame of a wide-angle lens example.

Figure 15 is a schematic view of a reflective element of a wide-angle lens example

16 is a schematic diagram showing an eccentric adjustment structure of a focusing unit of a rear mirror group component of a wide-angle lens example.

17 is a schematic diagram of an eccentric adjustment member mechanism of a wide-angle lens example.

Figure 18 is a schematic view showing the thread transmission structure of the focusing unit of the rear mirror unit of the wide-angle lens example.

detailed description

The invention will now be further described with reference to the accompanying drawings.

An imaging device of the present invention, as shown in FIG. 1, is composed of two identical first imaging systems and a second imaging system, the two imaging systems having the same imaging structure and being centrally symmetric with each other; The imaging structure includes a wide-angle lens that exceeds an angle of view of 180° and a sensor for capturing an image formed by the wide-angle lens.

The optical system consists of a first imaging system A and a second imaging system B, each using 8 lenses.

The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are in the first imaging system A and the second imaging system B corresponds to the first lens LA1, the second lens LA2, the third lens LA3, the fourth lens LA4, the fifth lens LA5, the sixth lens LA6, the seventh lens LA7, the eighth lens LA8, and the first lens LB1, respectively. The second lens LB2, the third lens LB3, the fourth lens LB4, the fifth lens LB5, the sixth lens LB6, the seventh lens LB7, and the eighth lens LB8.

The front lens group is composed of a first lens L1 and a second lens L2 disposed along a first optical axis, both of which are meniscus lenses having a negative focal length, and satisfy: Nd>1.7, Vd> 35, wherein the second lens L2 is close to the image side.

The rear mirror group is composed of a glass meniscus third lens L3 disposed along the second optical axis, a cemented glass biconcave fourth lens L4 and a glass biconvex fifth lens L5, and a glass biconvex sixth lens L6. The glued glass glass biconcave seventh lens L7 and the glass biconvex eighth lens L8 are composed. Wherein the eighth lens L8 is close to the image side;

The aperture stop is located between the third lens LA3 and the fourth lens LA4;

The focal length of the third lens L3 is positive, and satisfies: Nd>1.7;

The focal length of the fourth lens L4 is negative, and satisfies: Nd>1.7;

The focal length of the fifth lens L5 is positive, and satisfies: Nd>1.7;

The focal length of the sixth lens L6 is positive, and satisfies: Vd>48;

The focal length of the seventh lens L7 is negative, and satisfies: Nd>1.6;

The focal length of the eighth lens L8 is positive, and satisfies: Vd>48;

Wherein Nd represents a d-light refractive index of the lens material, and Vd represents a d-light Abbe constant of the lens material;

The first reflecting surface RA is disposed at a center and is at an angle of 45 degrees with both the first optical axis and the second optical axis, and the first optical axis and the second optical axis realize a 90° rotation of the optical axis through the first reflective surface RA;

An image sensor is mounted on the image side of the rear mirror group.

Further, the first lens L1, the third lens L3, the fourth lens L4, and the fifth lens L5 are both high refractive index glass lenses;

The eighth lens L8 is an ultra-low dispersion glass lens;

The second lens L2 and the sixth lens L6 are glass "double aspherical" lenses;

The fourth lens L4 and the fifth lens L5 are combined into a glue member, and the glue surface of the glue member is bent toward the image side;

The seventh lens L7 and the eighth lens L8 are collectively combined into a glue member, and the cemented surface of the glue member is bent toward the image side.

An image sensor is mounted on the image side of each wide-angle lens rear lens group. As shown in FIG. 1, SA and SB represent optical systems by image sensors in imaging system A and imaging system B, respectively.

The following data describes three examples of wide-angle lenses of the present invention.

These data apply to each individual optical imaging system.

Hereinafter, numerals 1 to 19 denote lens surfaces, pupil surfaces, and filter surfaces. "R" represents the radius of curvature of each surface and represents the "paraxial curvature" of the aspherical surface. "D" represents the surface pitch, "Nd" represents the refractive index of the d line, and "vd" represents the Abbe's coefficient. In addition, the object distance is infinity. The unit of length measurement is "mm".

The aspherical lens marked "*" in the table.

In this example, L2 and L6 are aspherical lenses, and the aspheric lens coefficient formula is as follows:

Z is the sag value of the lens, c is the reciprocal of the radius of curvature, h is the height from the edge of the lens to the optical axis, k is the conic coefficient, and A, B, C, D, and E represent the high-order aspheric coefficients, respectively.

Example 1:

The optical characteristic parameters of this example are: focal length F = 1.33, relative aperture Fno = 2.0, and field of view FOV = 190 degrees. Table 1 provides a set of lens parameters:

Surface number	R	D	Nd	Vd
OBJ	SPHERE		INF
1	15.100	0.9	1.8348	43
2	4.994	3.12
*3	67.865	0.85	1.8047	40
*4	3.500	2.35
5	INF	8	1.5168	64
6	INF	1
7	6.347	1.35	1.9228	twenty one
8	-83.900	1.2
STO	INF	0.5
9	-5.318	0.50	1.9459	18
10	19.250	1.73	1.8348	43
11	-5.422	0.3
*12	3.920	1.65	1.4950	81
*13	-13.820	0.36
14	-10.568	0.5	1.7283	28
15	3.051	2.9	1.4950	81
16	-4.656	0.21
17	INF	0.7	1.5168	64
18	INF	1.8
IMG

The aspheric coefficients of this example are listed in the following table:

Surface number	S3	S4	S12	S13
K	75.4223	-0.7847	-0.45	-3.4806
A	1.2522E-004	7.5887E-004	-4.6501E-004	3.8711E-003
B	-2.2324e-005	5.7804e-005	-1.8946E-004	-2.8180e-005

C	5.5633e-007	-8.5817e-006	-7.5788e-005	-6.0475e-005
D	-4.3473e-009	3.3873e-007	-1.4650e-006	-6.0525e-006
E	-9.2742e-027	-9.2761e-027	-9.2771e-027	9.2741e-027

2 is a schematic view of the MTF of the wide-angle lens in this example. In the figure, the horizontal axis represents the spatial frequency in units of line pairs per millimeter (lp/mm); the vertical axis represents the value of the modulation transfer function (MTF), and the value of the MTF is used to evaluate the imaging quality of the lens, and the value range is 0. -1, the higher the MTF curve, the better the image quality of the lens is, and the stronger the ability to restore the real image. 2 includes the diffraction limit 21, the axis 22, the R line 23 and the T line 24 at 0.3 Field (26.00°), and the T line 25 and the R line 26 at 0.7 Field (63.00°), 1.0 Field (94.99°). The R line 27 and the T line 28; from Fig. 2, the image quality is well corrected, and the output performance of more than 16 million pixels can be achieved.

FIG. 3 is a schematic diagram of the axial chromatic aberration of the wide-angle lens in the present example; generally, the lateral chromatic aberration is required to be within the range of the Airy. For the optical imaging system, the limit of the resolution of the imaging surface is measured by the diameter of the Ai Lie spot, and the radius of the Airy spot is r=1.22λf/d; if the lateral chromatic aberration is too large, the color unevenness on the imaged surface is found. It can be seen from Fig. 3 that the lateral chromatic aberration of light of different frequencies is mostly in the range of the Airy spot, and the imaging chromatic aberration is relatively uniform, that is, the axial chromatic aberration is well corrected, and clear imaging can be realized.

4 is a schematic diagram of the curvature of the field of the wide-angle lens in this example; the larger the field curvature, the more curved the line is when shooting a straight line. If there is one or more inflection points in the field curvature, the line that is seen becomes a curved curve. Line. It can be seen from Fig. 4 that the curvature of field is well corrected. Although there is a wide-angle field of view, the full field of view is relatively uniform.

FIG. 5 is a comparison diagram of the wide-angle lens in the present example; as shown in FIG. 5, it can be seen that the full-field field can maintain a contrast of more than 75%, so that the overall illumination of the image plane is uniform, and the shortcomings of some lenses on the market are avoided.

Through the appeal analysis, it shows that the wide-angle lens designed by the present invention maintains the resolution of the lens while maintaining the angle of view and the brightness of the surrounding, and the image pixels reach 16 million. Among them, the field of view angle of 190° can effectively reduce the image of the portion where the maximum field-of-view light flux of each lens does not overlap each other.

The following two examples are not specified.

Embodiment 2:

The optical characteristic parameters of this example are: focal length F = 1.28, relative aperture Fno = 2.03, and field of view FOV = 190 degrees.

Table 2 provides a set of lens parameters:

Surface number	R	D	Nd	Vd
OBJ	SPHERE		INF
1	15.482	1.1	1.8248	43
2	4.893	3.02
*3	87.000	0.85	1.76795	50
*4	3.400	1.98
5	INF	8	1.5168	64
6	INF	1
7	5.565	1.20	1.9212	twenty four
8	20.741	1.28
STO	INF	0.5

10	-5.706	0.88	1.9228	twenty one
11	-12.886	1.28	1.9108	35
12	-4.658	0.10
*13	3.694	1.695	1.4950	81
*14	-14.427	0.96
15	-46.060	0.5	1.80518	25
16	3.486	2.271	1.4950	81
17	-4.666	0.5
18	INF	0.7	1.5168	64
19	INF	1.55
IMG

The aspheric coefficients of this example are listed in the following table:

Surface number	S3	S4	S11	S12
K	-99.00	-0.7759	-0.5145	23.1018
A	7.1159e-004	1.0255e-003	-4.3977e-004	6.0740e-003
B	-5.6583e-005	6.9844e-005	2.1293e-004	1.7817e-004
C	1.4175e-006	-1.6269e-005	-5.1714e-005	-4.6786e-005
D	-1.3178e-008	6.0862e-007	3.9490e-006	2.4520e-006
E	-1.1115e-025	-1.1118e-025	-1.1118e-025	-1.1118e-025

6 and 7 are a schematic structural view and a field curvature and axial chromatic aberration diagram of Example 2, respectively.

Embodiment 3:

The optical characteristic parameters of this example are: focal length F = 1.35, relative aperture Fno = 2.01, and field of view FOV = 190 degrees.

Table 3 provides a set of lens parameters:

Surface number	R	D	Nd	Vd
OBJ	SPHERE		INF
1	14.543	1.1	1.8348	43
2	4.973	3.14
*3	84.109	0.85	1.8099	41
*4	3.400	1.9

5	INF	8	1.5168	64
6	INF	1
7	6.144	1.34	1.9212	twenty four
8	-88.400	1.09
STO	INF	0.5
9	-5.806	0.61	1.9228	twenty one
10	13.619	1.96	1.8348	43
11	-5.768	0.10
*12	3.753	1.63	1.4950	81
*13	-22.204	0.4
14	-11.249	0.5	1.7282	28
15	3.150	2.8	1.4950	81
16	-4.543	1
17	INF	0.7	1.5168	64
18	INF	0.77
IMG

The aspheric coefficients of this example are listed in the following table:

Surface number	S3	S4	S11	S12
K	24.3102	-0.7689	-0.3492	-26.0439
A	1.2764e-004	7.5236e-004	-2.0250e-004	4.4142e-003
B	-2.5724e-005	7.9076e-005	2.2732e-004	1.8923e-004
C	8.4391e-007	-1.1739e-005	-9.0795e-005	-8.9662e-005
D	-9.0796e-009	5.9197e-007	5.5758e-006	-2.5272e-006
E	-9.2715e-025	-9.2773e-025	-9.2773e-025	-9.2773e-025

8 and 9 are respectively a schematic structural view of the third example and a schematic diagram of field curvature and axial chromatic aberration.

Figure 10 is a half cross-sectional view showing the use state of the wide-angle lens of the embodiment, the first wide-angle lens of the first imaging system and the second wide-angle lens of the second imaging system have separate holders 1, reflective elements 12, and the cage By combining the connecting devices, the optical axes of the front lens group member 2 of the first wide-angle lens and the front lens group member 2 of the second wide-angle lens are aligned and the lens arrangement directions are opposite to each other, and the rear lens group member 3 of the first wide-angle lens and The optical axes of the rear mirror group members 3 of the second wide-angle lens are parallel or at an angle to each other. Figure 10 shows the angle of the optical axis of the two rear mirror assembly members 3 In the reverse 180 degrees, the lateral distance between the front mirror assembly 2 of the two wide-angle lenses is minimized.

As shown in FIG. 11-13, when the optical axis angles of the first imaging system and the second imaging system rear mirror group 3 are 0, 90, and 135 degrees respectively, the relative angles of the two wide-angle lenses in the imaging system are respectively position.

It can be seen from Fig. 11-13 that according to the customer's requirements, the coupling device between the two wide-angle lenses can be changed, the two optical systems are still independent, and the customization characteristics are strong.

Figures 11-13, also showing that rotating the angle of one of the imaging systems can shorten the longitudinal distance between the two rear mirror sets. In particular, as shown in Fig. 11, when the optical axes of the rear mirror group members 3 of the two imaging systems are in the same direction at 0 degrees, the longitudinal distance is the shortest.

Next, the fixing method and apparatus of the imaging system will be described with reference to the state of use of the wide-angle lens in FIG.

As shown in FIG. 14, the frame body 11 is provided with a positioning circular hole 111 and a positioning cylinder 112. The frame body 11 is provided with two mounting circular holes, one of which is a mounting circular hole 113 and the other is a mounting circular hole 114. The frame body 11 is provided with a focusing hole 115. The positioning circular hole 111 has the same diameter as the positioning cylinder 112, and the positional distribution of the positioning circular hole 111 and the positioning cylinder 112 is such that the vertical distance between the two is equal to the optical axis of the front mirror assembly 2. The position of the mounting circular holes 113 and 114 is such that the vertical distance between the two to the optical axis of the rear mirror assembly 3 is equal.

As shown in Fig. 15, the reflective surface element 12 is a right-angled triangular prism having a hypotenuse of 45°. The reflective surface element 12 has an antireflection film on the S1 surface and the S3 surface of the right angle prism, and the S2 surface is plated with a reflection film.

The specific installation process and steps are as follows: First, an optical imaging system and a reflective element 12 are mounted on the frame 11, the optical imaging system is equipped with a wide-angle lens having an angle of view exceeding 180 degrees, and the wide-angle lens includes a front lens group. Part 2 and rear mirror assembly unit 3. The reflective element 12 is mounted on a corresponding mounting surface of the frame body 11. The front mirror assembly 2 is mounted on a mirror mounting surface corresponding to the front tube of the cage 1, and the rear mirror assembly 3 is mounted in the rear tube of the cage 1. So far, a single optical imaging system has been assembled.

The two separate optical imaging systems are then substantially aligned in line with the optical axis of the front mirror assembly 2, and the optical axis of the rear mirror assembly 3 is approximately 180 degrees aligned. The positioning cylinders 112 on the respective optical imaging system frames 11 are respectively corresponding to the positioning circular holes 111 on the other optical imaging system frame 11, aligned and loaded. At this time, the positions of the mounting holes 113 and 114 on the two optical imaging system frames 11 are also automatically aligned. Finally, two locking screws are inserted into the mounting hole 113 and the mounting hole 114.

So far, the fixed mounting process of the image forming apparatus described in the present example is completed.

The use of a prism as a reflective element enables the optical path to be reversed by 90°, greatly reducing the image of the portion of the lens where the maximum field-of-view angular flux does not overlap, and with a wide-angle lens of 190°, full-angle imaging is achieved. By assembling two separate optical imaging systems with an angle of view of more than 180 degrees of view, the purpose of obtaining an image with a solid angle of 4π is achieved, and the production difficulty of the frame 11 is reduced.

The focusing mode of the image forming apparatus described in the present example is that the position of the image plane is constant, and the relative position of the mirror group 3 in the holder 1 is adjusted to realize the function of adjusting the back focus distance. The manner in which the rear mirror assembly 3 is moved in the cage 1 is eccentrically adjusted, threaded, and the like.

The eccentrically adjusted transmission mode includes a cage 1, a rear mirror assembly 3, and an eccentric adjustment member 4.

As shown in FIG. 16, the holder 1 has a focusing hole 115 having a diameter of 2 mm. The surface of the rear mirror assembly member 3 includes an annular groove 31 having a width of 1.4 mm.

There is no less than one length of inner and outer diameter fitting relationship between the retainer 1 and the rear mirror assembly 3, and the rear mirror assembly 3 is relatively slidable in the retainer 1. The mating surface has two sections, which are a long fitting surface 121 and a short fitting surface 122, respectively.

As shown in FIG. 17, the eccentric adjusting member 4 is divided into four segments, and the eccentric post 41, the fitting post 42, the bearing post 43, and the rotating post 44 are respectively small to large in accordance with the outer diameter. The eccentric post 41 has a diameter of 1 mm and is inscribed with the outer circle of the mating post 42. The diameter of the matching column 42 is 2 mm, which is the same as the diameter of the focusing hole 115 on the cage 1. During the actual focusing process, the matching column 42 is matched with the focusing hole 115. The outer end surface of the bearing column 43 is a seating surface 431 which bears against the outer surface 1151 of the focusing circular hole 115. The rotating column 44 is a hand-held rotating portion, and the eccentric post 41 is driven by the rotation of the rotating column 44. Do circular motion.

By rotating the rotating column on the eccentric adjusting member 4, the eccentric post 41 is moved forward and backward, and since the eccentric post 41 is in tangent contact with the annular groove 31 on the rear mirror unit 3, the rear mirror unit 3 is in the cage 1. The axial fine adjustment motion realizes the function of adjusting the back focus distance of the rear mirror assembly unit 3. The focus adjustment between the two single-sided optical imaging systems in the full-view optical imaging system does not affect each other, which reduces the difficulty of focusing of the full-field optical imaging system.

The specific installation and focusing process of the eccentric drive is as follows:

First, the rear mirror group member 3 is first loaded into the holder 1, and the corresponding annular groove 31 is substantially corresponding to the position of the focusing circular hole 115 of the main body tube member, and the other components of the full-view optical imaging system are assembled and image detection is performed.

Using the eccentric adjustment member 4, the eccentric post is inserted into the focusing hole 115, the bearing surface 431 bears against the outer surface 1151 of the focusing hole, and the eccentric column is in contact with the annular groove 31, and the eccentric column is rotated by the rotating column 44. 41 is in a state of being tangential to the annular groove 31.

The annular groove 31 undergoes an axial fine adjustment movement, and the rear mirror assembly 3 undergoes an axial fine adjustment movement. According to the size of the annular groove 31, the focusing circular hole 115, the eccentric column 41, and the fitting column 42, the adjustment amount of the front and rear fine adjustment movement can be calculated to be ±0.3 mm. This trimming amount is sufficient to satisfy the back focus adjustment of the system.

Based on the image effect, it is determined whether or not the back focus adjustment is completed. If completed, an adhesive is added to the focus round hole 115 and the annular groove 31 to fix the relative position of the rear mirror unit 3 and the holder 1.

The focusing process of the other side rear mirror unit 3 is the same. So far, the focusing process of the full-view optical imaging system is completed.

Another type of focusing mode in which the rear mirror unit 3 is moved in the holder 1 is a threaded transmission. Let's make a brief description below.

The threaded transmission mode is the simplest transmission method that changes the rotary motion into a linear motion, and the mechanism includes the cage 1 and the rear mirror assembly 3. As shown in FIG. 18, the cage 1 includes a frame body 11. The frame 11 has an empty slot 116. The rear mirror assembly member 3 is a cylindrical member, so that the amount of rotation of itself can be converted into an axial movement amount. The rear mirror assembly 3 has a section of drive threads 32 that cooperate with the retainer 1 and the rear mirror assembly 3 has a mating relationship with the retaining body 1 of no less than one length. The fitting relationship includes a long fitting surface 121 and a short fitting surface 122. At the long fitting surface, the rear mirror group 3 has a uniformly distributed key groove 33 at its periphery. The outer portion of the cage 1 has an empty recess 116 which allows direct viewing of the exposed rear mirror assembly 3 from the outside. An external force acts on the keyway 33 on the rear mirror assembly 3 such that the drive threads 32 on the rear mirror assembly 3 are threaded with the cage 1 such that the rear mirror assembly 3 is stable and accurate in the cage 1 Movement to achieve back focus adjustment.

Although the invention has been described by way of example, it is not limited thereto. It will be appreciated by those skilled in the art that various modifications of the above-described embodiments are possible without departing from the scope of the invention as defined by the appended claims.

Claims (5)

1. An imaging device consisting of two identical first imaging systems and a second imaging system, the two imaging systems having the same imaging structure and being centrally symmetric with each other; the imaging structure comprising a field of view over 180° a wide-angle lens of an angle and a sensor for taking an image formed by the wide-angle lens;

   The wide-angle lens includes a front mirror assembly, a reflective member, and a rear mirror assembly, which are arranged from the object side to the image side, and the optical axis of the front mirror assembly is bent toward the rear mirror assembly by the reflection of the reflective member; An imaging system and an image taken by the second imaging system are combined to obtain an image having a solid angle of 4π, which is characterized by:

   The first wide-angle lens of the first imaging system and the second wide-angle lens of the second imaging system have separate holders and reflective elements, and the holders are coupled together by a connecting device such that the front lens assembly and the first wide-angle lens The optical axes of the front lens assembly components of the two wide-angle lenses are aligned and the lens arrangement directions are opposite to each other, and the optical axes of the rear mirror assembly of the first wide-angle lens and the rear mirror assembly of the second wide-angle lens are parallel or at an angle to each other.
2. The image forming apparatus according to claim 1, wherein said holder comprises a front tube for mounting the front mirror assembly and a rear tube for mounting the rear mirror assembly, said front and rear tubes The optical axes are perpendicular to each other; a reflective element is disposed in the connecting portion between the front tube and the rear tube, and a platform is disposed on the connecting portion, the platform is parallel to the optical axis of the front tube and perpendicular to the optical axis of the rear tube, and the platform There is a mounting hole in the upper opening;

   The connecting device for connecting the cage comprises the above-mentioned platform and mounting circular hole, and further comprises a positioning circular hole disposed at the end of the front tube and a positioning cylinder disposed on the side wall of the rear tube, and the positioning cylinder of the cage is inserted into another retaining cylinder In the positioning hole of the frame, the platform of the cage is fitted with the platform of the other cage, so that the mounting holes on the two cages are aligned and the screws are loaded.
3. The image forming apparatus according to claim 2, wherein the function of the back focus adjustment is realized by adjusting the relative positions of the rear mirror group members in the holder; the rear mirror unit member moves back and forth along the optical axis direction in the holder The rear mirror assembly and the retainer are not less than a fitting relationship, and the outer side of the rear mirror assembly has a ring groove or other iconic design corresponding to the initial position of the cage; after the initial position is substantially corresponding, the rear mirror assembly is adjusted by an external force. In the relative position in the cage, the focus adjustment is confirmed according to the actual imaging device effect, and finally the rear mirror assembly member is fixed in the holder.
4. The image forming apparatus according to claim 3, wherein the specific structure of the relative position of the rear mirror unit 3 in the holder 1 is such that the rear mirror unit 3 has a thread which is engaged with the holder 1, the holder 1 There is an empty groove outside, and the rear mirror group 3 is rotated by external stress to realize a stable and accurate linear motion of the rear mirror assembly 3 in the cage 1.
5. The image forming apparatus according to claim 3, wherein the specific structure of the relative position of the rear mirror unit 3 in the holder 1 is: the eccentric adjustment member 4 is inserted into the adjustment circular hole 115 outside the holder, and the adjustment circle is adjusted. The outer end surface 1151 of the hole 115 is a reference plane that cooperates with the bearing surface of the eccentric adjusting member 4; the eccentric adjusting member 4 is divided into four segments whose outer diameter gradually increases from the inside to the outside: the eccentric column 41, the fitting column 42, and the bearing column 43. The rotating column 44, wherein the eccentric column 41 and the outer circle of the matching column 42 are inscribed, and the matching column 42 has the same diameter as the focusing hole 115. During the actual focusing process, the matching column 42 and the focusing hole 115 are matched. The outer end surface of the bearing column 43 is a bearing surface 431 which bears against the outer surface 1151 of the focusing hole 115; the rotating column 44 is a hand-held rotating portion, and the rotation of the rotating column 44 drives the eccentric column 41 to perform a circular motion; The eccentric post 41 is in contact with and tangential to the annular groove 31 of the rear mirror assembly member 3, and the eccentric post 41 drives the rear mirror assembly 3 to fine-tune the movement.

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