WO2019024536A1

WO2019024536A1 - Rotating zoom lens system and method for realizing same

Info

Publication number: WO2019024536A1
Application number: PCT/CN2018/083011
Authority: WO
Inventors: 滕少华; 霍颖翔; 滕璐瑶; 张巍
Original assignee: 滕少华; 霍颖翔; 滕璐瑶; 张巍
Priority date: 2017-08-02
Filing date: 2018-04-13
Publication date: 2019-02-07
Also published as: CN107490847A; CN107490847B

Abstract

Provided are a rotating zoom lens system and a method for realizing the same. The rotating zoom lens system comprises a first lens assembly (1), a second lens assembly (2), and a liquid crystal module (3). An optical axis of the first lens assembly (1) and an optical axis of the second lens assembly (2) are arranged on the same straight line. A focal length of the stacked first lens assembly (1) and second lens assembly (2) changes with a change in relative angles of the first lens assembly (1) and second lens assembly (2). The liquid crystal module (3) is installed at one side of the first lens assembly (1) or one side of the second lens assembly (2). The rotating zoom lens system performs zooming by changing relative angles of lens assemblies without having to adjust a distance between the lens assemblies, such that the system has a compact size, can be manufactured easily, and is applicable to the field of optical instruments.

Description

Rotary zoom lens system and implementation method thereof

Technical field

The invention relates to the field of optical instruments, in particular to a rotary zoom lens system and an implementation method thereof.

Background technique

The continuous zoom optical system refers to an optical system in which the focal length continuously changes within a certain range, the image plane position remains unchanged during zooming, the relative aperture is also substantially unchanged, and the image quality remains good during zooming. In general, the relative aperture of the system is constant during the process of changing the focal length. The zoom system fully utilizes the zooming ability. With the practical use of autofocus technology and the advancement of processing technology, on the basis of ensuring the image quality, the zoom optical lens introduces many new design ideas. The focus mode or the aspherical use has been carefully studied, making the subsequent miniaturization and miniaturization feasible, and also prompted the emergence of zoom lens lenses.

At present, on cameras and projectors, the traditional design method is to form a lens system by using a plurality of lenses to be superimposed, and then to change the focal length by changing the distance between the lenses in the lens system, but by adjusting the lens between The distance to achieve zooming will inevitably lead to the system needing to reserve more space, and the system is bulky. When manufacturing such a lens system, it is necessary to ensure that the central optical axes of the lenses are aligned before and after the movement, which is difficult to manufacture.

Summary of the invention

In order to solve the above technical problems, an object of the present invention is to provide a rotary zoom lens system which is small in size and simple in manufacture.

Another object of the present invention is to provide an implementation method of a rotary zoom lens system that is small in size and simple to manufacture.

The technical solution adopted by the present invention is:

A rotary zoom lens system comprising a first lens group, a second lens group, and a liquid crystal module, wherein an optical axis of the first lens group and an optical axis of the second lens group are on a same line, the first lens group and The focal length of the second lens group superimposed changes as the relative angles of the first lens group and the second lens group change, and the liquid crystal module is mounted on one side of the first lens group or on one side of the second lens group.

Further, each of the first lens group and the second lens group includes at least one lens, and a focal length of the lens changes as a radial angle changes.

Further, the first lens group includes a first single-sided convex lens, and the second lens group includes a second single-sided convex lens, the first single-sided convex lens and the second single-sided convex lens are the same, the first single-sided convex lens The plane is opposite to the plane of the second single-sided convex lens, and the liquid crystal module is mounted between the first single-sided convex lens and the second single-sided convex lens.

Further, the cylindrical coordinate surface surface equation of the first single-sided convex lens is:

Where f is the focal length value, ω is the refractive index, m is the distance from the point on the curved surface to the center of the lens, and r is the distance from the point on the curved surface to the center of the circle.

Further, the first single-sided convex lens is a Fresnel lens, and the cylindrical coordinate surface surface equation of the Fresnel lens is:

Where τ is the Fresnel lens pitch,

The amount of lens thickness cut as a function of the polar diameter produced by Fresnel lensing.

Further, the edge of the first single-sided convex lens is further provided with a tooth structure.

Further, the main bracket further includes an opening, and the liquid crystal module is embedded in the opening.

Further, the method further includes a stepping motor, a driving belt, a power wheel and a first rotating shaft, wherein the stepping motor and the first rotating shaft are fixedly connected with the main bracket, and the power wheel is mounted on the first rotating shaft, and the power wheel is The first single-sided lens is engaged, and the stepping motor and the power wheel are driven by a drive belt.

Further, further comprising a support wheel and a second rotating shaft, the second rotating shaft is fixedly coupled to the main bracket, the supporting wheel is mounted on the second rotating shaft, and the supporting wheel is engaged with the first single-sided convex lens.

Another technical solution adopted by the present invention is:

A method for implementing a rotary zoom lens system includes the following steps:

Calculating a surface surface equation of a lens in the first lens group and a lens in the second lens group;

Calculating an occlusion region of the liquid crystal module according to a surface curvature equation of the lens in the first lens group and the lens in the second lens group;

The rotary zoom lens system is obtained based on the surface curved surface equation of the lens in the first lens group, the surface curved surface equation of the lens in the second lens group, and the occlusion region of the liquid crystal module.

Further, the lens in the first lens group is a first single-sided convex lens, and the lens in the second lens group is a second single-sided convex lens, and the first single-sided convex lens and the second single-sided convex lens are the same .

Further, the calculating a surface surface equation of the lens in the first lens group and the lens in the second lens group includes:

Enter the shortest focal length, the longest focal length, the light transmittance, and the refractive index of the material of the rotating zoom lens system;

According to the focal length superposition theorem, a composite focal length function of the first single-sided convex lens and the second single-sided convex lens in a Cartesian coordinate system is obtained, and the expression of the synthetic focal length function is:

Ω(f ₁ ,f ₂ )=(f ₁ *f ₂ )/(f ₁ +f ₂ );

Wherein f ₁ is a focal length of the first single-sided convex lens, and f ₂ is a focal length of the second single-sided convex lens;

Performing a distortion transformation on the composite focal length function in the Cartesian coordinate system according to the shortest focal length, the longest focal length, the light transmittance, and the refractive index of the material to obtain a focal length function after the distortion transformation of the first single convex lens and the second single convex lens, The expression of the twisted transformed focal length function is:

Where Z ₀ = 2Z _c , Z _c is the central focal length, Z ₀ is twice the central focal length, intermediate variable function

The expression for the intermediate variable x is:

Where v _H is the maximum value of the intermediate variable x, v _L is the minimum value of the intermediate variable x, x ∈ (v _L , v _H ),

Radial angle

A radial derivative function of the first single-sided convex lens and the second single-sided convex lens is obtained according to the focal length function after the distortion transformation, and the expression of the radial derivative function is:

Where f is the focal length value, ω is the refractive index, and r is the distance from the point on the curved surface to the center of the circle;

Integrating the obtained radial derivative function to obtain a surface surface equation of the first single-sided convex lens and the second single-sided convex lens, and the expressions of the surface surface equations of the first single-sided convex lens and the second single-sided convex lens are:

Where m is the distance from the point on the surface to the center of the lens.

Further, the calculating a surface surface equation of the lens in the first lens group and the lens in the second lens group, the step further comprising: converting the first single convex lens and the second single convex lens into a Fresnel The surface equation of the lens after the first single-sided convex lens and the second single-sided convex lens are converted into a Fresnel lens is:

Where τ is the pitch of the Fresnel lens,

Further, the expression of the occlusion region of the liquid crystal module in polar coordinates is:

or

among them,

For the radial angle of the lens, m is the distance from the point on the curved surface to the center of the lens, m ₂ is the radius of the second single-sided convex lens, τ is the pitch, φ() is the function of the radial angle, and μ is a positive integer. , ι is the extended length, ε is the count value used for exhaustive and ι, and θ is the first single-sided convex lens and the second single-sided convex lens

The angle of the place.

The rotary zoom lens system of the present invention has the beneficial effects of including a first lens group, a second lens group, and a liquid crystal module, wherein the focal lengths of the first lens group and the second lens group are changed with the relative angles of the two lens groups. The change, combined with the liquid crystal module, allows the lens system to zoom by changing the relative angle between the lens groups, eliminating the need to adjust the distance between the lens groups to zoom, saving space, making the system small in size and simple to manufacture. .

The method of the present invention has the beneficial effects of: calculating a surface surface equation of a lens in the first lens group and a lens in the second lens group, calculating an occlusion region of the liquid crystal module according to the surface surface equation, and according to the surface The surface equation and the occlusion region of the liquid crystal module, the steps of the rotary zoom lens system are obtained, and the first lens group, the second lens group and the liquid crystal module in the rotary zoom lens system of the present invention can be realized, so that the lens system can be changed between the lens groups The relative angle of the zoom is no longer necessary to adjust the distance between the lens groups to zoom, saving space, making the system small in size and simple to manufacture.

DRAWINGS

1 is a schematic cross-sectional view of a rotary zoom lens system of the present invention;

2 is an exploded view showing the structure of a rotary zoom lens system of the present invention;

3 is a first function diagram of superimposed focal lengths of the first lens group and the second lens group;

4 is a second function diagram of a superimposed focal length of the first lens group and the second lens group;

5 is a flow chart showing an implementation method of a rotary zoom lens system according to a fourth embodiment of the present invention;

6 is a schematic view showing a radial halving cutting method of a Fresnel lens in the implementation method of the rotary zoom lens system of the present invention;

Figure 7 is a graph showing the relationship between w _L , w _H , v _L , v _H and k in the implementation method of the rotary zoom lens system of the present invention.

Detailed ways

Referring to FIG. 1, a rotary zoom lens system includes a first lens group 1, a second lens group 2, and a liquid crystal module 3. The center of the first lens group 1 and the center of the second lens group 2 are coaxial, The focal lengths after the superposition of the first lens group 1 and the second lens group 2 vary with the relative angles of the first lens group 1 and the second lens group 2, and the liquid crystal module 3 is mounted on one side of the first lens group 1. Or one side of the second lens group 2.

Further as a preferred embodiment, each of the first lens group 1 and the second lens group 2 includes at least one lens, and the focal length of the lens changes as the radial angle changes.

Further as a preferred embodiment, the first lens group 1 includes a first single-sided convex lens, and the second lens group 2 includes a second single-sided convex lens, the first single-sided convex lens and the second single-sided convex lens are the same, The plane of the first single-sided convex lens is opposite to the plane of the second single-sided convex lens, and the liquid crystal module 3 is mounted between the first single-sided convex lens and the second single-sided convex lens.

Further as a preferred embodiment, the cylindrical coordinate surface surface equation of the first single-sided convex lens is:

Further as a preferred embodiment, the first single-sided convex lens is a Fresnel lens, and the cylindrical coordinate surface surface equation of the Fresnel lens is:

Where τ is the Fresnel lens pitch,

Further as a preferred embodiment, the edge of the first single-sided convex lens is further provided with a tooth structure.

Referring to FIG. 2, further as a preferred embodiment, a main bracket 4 is further included. The main bracket 4 is provided with an opening, and the liquid crystal module 3 is embedded in the opening.

Referring to FIG. 2, further as a preferred embodiment, a stepping motor 5, a transmission belt 6, a power wheel 7 and a first rotating shaft 8 are further included. The stepping motor 5 and the first rotating shaft 8 are fixedly connected to the main bracket 4, The power wheel 7 is mounted on a first rotating shaft 8, the power wheel 7 is meshed with a first single-sided lens, and the stepping motor 5 and the power wheel 7 are driven by a transmission belt 6.

Referring to FIG. 2, further as a preferred embodiment, further comprising a support wheel 9 and a second rotating shaft 10, the second rotating shaft 10 is fixedly connected with the main bracket 4, and the supporting wheel 9 is mounted on the second rotating shaft 10, The support wheel 9 is meshed with the first single-sided convex lens.

Calculating a surface surface equation of a lens in the first lens group 1 group and a lens in the second lens group 2 group;

Calculating an occlusion region of the liquid crystal module 3 according to a surface curvature equation of a lens in the first lens group 1 group and a lens in the second lens group 2 group;

The rotary zoom lens system is obtained from the surface curved surface equation of the lens in the first lens group 2 group, the surface curved surface equation of the lens in the second lens group 2 group, and the occlusion region of the liquid crystal module 3.

Further, as a preferred embodiment, the lens in the first lens group 1 is a first single-sided convex lens, and the lens in the second lens group 2 is a second single-sided convex lens, the first single-sided convex lens Same as the second single-sided convex lens.

Further as a preferred embodiment, the calculating the surface surface equation of the lens in the first lens group 1 group and the lens in the second lens group 2 group, the steps include:

Ω(f ₁ ,f ₂ )=(f ₁ *f ₂ )/(f ₁ +f ₂ );

The expression for the intermediate variable x is:

Radial angle

Further as a preferred embodiment, the calculating a surface surface equation of the lens in the first lens group 1 and the lens in the second lens group 2, the step further comprising: the first single convex lens and the second single The surface convex lens is converted into a Fresnel lens, and the surface surface equation after the first single-sided convex lens and the second single-sided convex lens are converted into a Fresnel lens is:

Where τ is the pitch of the Fresnel lens,

Further as a preferred embodiment, the expression of the occlusion region of the liquid crystal module 3 in polar coordinates is:

or

among them,

The angle of the place.

A first embodiment of the invention is given in connection with Figure 1:

The lens system of the present embodiment mainly includes a first lens group 1, a second lens group 2, and a liquid crystal module 3.

Wherein, the central optical axes of the first lens group 1 and the second lens group 2 are aligned, and the two can be relatively rotated with the central axis as a rotating axis, and the superimposed focal length of the first lens group 1 and the second lens group 2 follows the first lens. The relative angles of the group 1 and the second lens group 2 vary.

The liquid crystal module 3 can be mounted in three ways, the first is installed between the first lens group 1 and the second lens group 2, and the second is mounted on one side of the first lens group 1 and not with the second lens. The group 2 is adjacent, the third is mounted on one side of the second lens group 2 and is not adjacent to the first lens group 1, and the liquid crystal module 3, the first lens group 1 and the second lens group 2 are closely mounted, There are no gaps in the middle.

The structure in which the first lens group 1 and the second lens group 2 are superimposed by a plurality of lenses (which may be Fresnel lenses) may make the focal length parameter of the lens group closer to an ideal lens as long as the first lens group 1 and the second lens are matched. The superimposed focal length of the group 2 may be changed as the relative angles of the first lens group 1 and the second lens group 2 change, and the number of lenses and the lens parameters may be flexibly adjusted according to actual conditions.

A second embodiment of the invention is given in connection with Figure 2:

The lens system of the present embodiment mainly includes a first lens group 1, a second lens group 2, and a liquid crystal module 3. The first lens group 1 is a first single-sided convex lens, and the second lens group 2 is a second single-sided convex lens.

Wherein, the first single-sided convex lens and the second single-sided convex lens are the same single-sided convex lens (having a plane and a curved surface), and the two single-sided convex lenses are single-sided convex lenses whose focal length changes with a radial angle change; The first single-sided convex lens and the second single-sided convex lens are opposite in plane, and the central optical axis is on the same axis, and the liquid crystal module 3 is sandwiched between the first single-sided convex lens and the second single-sided convex lens, the first The single-sided convex lens, the second single-sided convex lens, and the liquid crystal module 3 are closely mounted with no gap therebetween, and the first single-sided convex lens and the second single-sided convex lens are relatively rotatable about the axis.

The first single-sided convex lens and the second single-sided convex lens can be realized by a special circular single-sided convex lens. The cylindrical coordinate surface surface equation of the special circular single-sided convex lens is:

f can be represented by F(x, Z ₀ ), and its expression is:

Z _c is the central focal length, Z ₀ = 2Z _c ; the expression of x is:

Indicates the radial angle of the lens, x ∈ (v _L , v _H ).

The edge of the first uniplanar convex lens is further provided with a toothed structure for engaging with the transmission mechanism.

Referring to Fig. 2, the lens system of the present invention further includes a main support 4, a stepping motor 5, a drive belt 6, a power wheel 7, a first rotating shaft 8, a support wheel 9, and a second rotating shaft 10.

The main bracket 4 has an opening having the same shape as that of the liquid crystal module 3. The liquid crystal module 3 is embedded in the opening of the main bracket 4, and the main bracket 4 is used to support the components.

The stepping motor 5, the first rotating shaft 8, and the second rotating shaft 10 are all fixed on the main bracket 4, the power wheel 7 is mounted on the first rotating shaft 8, and the upper half of the power wheel 7 is the first pulley The lower half is a gear, the first pulley is engaged with the first single-sided lens, the stepping motor 5 is mounted with a second pulley, and the transmission belt 6 is mounted on the first pulley and the second pulley. The support wheel 9 is mounted on the second rotating shaft 10 to form a supporting assembly and is engaged with the first single-sided convex lens. The supporting wheel 9 can be realized by a common gear for supporting the first single-sided convex lens to ensure its rotation. Smooth and no offset in the center. The support assembly has three groups and each meshes with a first single-sided convex lens, and the three sets of support assemblies and the power wheel 7 constitute four fulcrums of the first single-sided convex lens. The stepping motor 5 is used to drive the power wheel 7 through the transmission belt 6 to rotate the first single-sided convex lens.

A third embodiment of the invention:

The first single-sided convex lens and the second single-sided convex lens in the second embodiment may also be implemented by a circular Fresnel lens, and the cylindrical coordinate surface surface equation of the circular Fresnel lens is:

Where the expression of S(f, ω, m) is:

τ is the Fresnel lens pitch, f is the focal length value, ω is the refractive index of the material, and m is the distance from the point on the curved surface to the center of the lens.

Substituting S(f,ω,m)

The working principle of the rotary zoom lens system of the present invention is exemplified below:

Taking the lens group in which the focal length of the first lens group 1 and the second lens group 2 are changed as the radial angle changes, f ₁ and f ₂ are respectively the focal lengths of the two lens groups, and the focal length function of the two lens groups is Ω. The (f ₁ , f ₂ ) expression is:

Since the two lens groups are the same (that is, the focal length parameters are the same), and the mounting direction is opposite, that is, the focal lengths of the two lens groups are relative when rotating, so at any time, if

Must have

among them

Is the focal length function of the lens group,

The radial angle of the lens group. However, the focal length of the two lens groups in the present invention varies with the radial angle, so the focal length function of the lens group

It is a curve, so the focal length function Ω(f ₁ , f ₂ ) after superposition of the two lens groups is shown in Fig. 3. As can be seen from FIG. 3, by the focal length variation characteristic of the lens group of the present invention, the superimposed result of the two lens groups can be equivalent to a common lens having a uniform focal length in the radial direction.

Let θ be the two lens group

The angle of the place. If the lens group having the characteristics of the focal length parameter shown in FIG. 3 is still used, and the first lens group 1 is rotated by π/2 radians, that is, θ=π/2, the superimposed focal length of the two lens groups is changed, and the effect after the change is as follows. As shown in Fig. 4, the superimposed focal length of the two lens groups produces two steps, which indicates that by changing the relative angles of the two lens groups, it is possible to cause the lens system to produce two different focal lengths in portions in different radial directions. By using the liquid crystal module 3 to block the radial sector corresponding to the lens group at the high step of the right half shown in Fig. 4, or to block the sector where the left step is located, the lens system will become a rotating zoom lens system close to a single focal length.

A fourth embodiment of the invention:

A method for implementing the rotary zoom lens system, the implementation method mainly comprises the following steps:

S1. Calculating a surface curvature equation of a lens in the first lens group 1 group and a lens in the second lens group 2 group;

S2. Calculating an occlusion region of the liquid crystal module 3 according to a surface curvature equation of a lens in the first lens group 1 group and a lens in the second lens group 2 group;

S3. A rotary zoom lens system is obtained according to a surface curved surface equation of a lens in the first lens group 1 group, a surface curved surface equation of a lens in the second lens group 2 group, and an occlusion region of the liquid crystal module 3.

Referring to FIG. 5, the first lens group 1 is the first single-sided convex lens and the second lens group 2 is the second single-sided convex lens, and the first single-sided convex lens and the second single-sided convex lens are the same as the steps S1-S2. Detailed description.

The step S1 includes:

S101. Input shortest focal length, longest focal length, light transmittance and material refractive index of the rotary zoom lens system;

The longest focal length Z _max and the shortest focal length Z _min should meet the following relationship:

Where T() is the inverse function of the focal length function F(), Z _c is the central focal length (the composite focal length of the lens system when the relative angle of the first single-sided convex lens and the second single-sided convex lens is θ=0), and f is the focal length. Substituting f into F ^-1 (x, Z ₀ ) yields F ^-1 (f, Z ₀ ).

Referring to FIG. 7, the range of the transmittance k should be in the following relationship:

Where v _H is the maximum value of the focal length of the lens system corresponding to the minimum transmittance in the function T() domain, and v _L is the lens system corresponding to the minimum transmittance in the function T() domain. The minimum value of the focal length that can be obtained, w _L is the corresponding value of the shortest focal length Z _min of the unilateral convex lens in the function T() domain, and w _H is the maximum focal length Z _max of the unilateral convex lens corresponding to the function T() domain. The value, w _L = T(Z _min , Z ₀ ); w _H = T(Z _max , Z ₀ ), T() is the inverse function of the focal length function F().

S102. Calculate the systematic error by using an error formula to determine the rationality of the current shortest focal length, the longest focal length, the transmittance, and the refractive index of the material. If the error is small, the value is reasonable, and the expression of the error formula is expressed. The formula is:

Where m is the focal length.

S103. In the original direct coordinate system, obtain a composite focal length function of the first single-sided convex lens and the second convex lens according to a focal length superposition theorem, and the expression of the synthetic focal length function is:

Ω(f ₁ ,f ₂ )=(f ₁ *f ₂ )/(f ₁ +f ₂ );

S104. According to the relationship between the synthetic focal length function and Z ₀ in the original Cartesian coordinate system, Equation (1) can be obtained:

Wherein, x ₁ and x ₂ variables, C is a constant real number, F(x ₁ )=f ₁ , F(x ₂ )=f ₂ .

The expression of the focal length function of the first single-sided convex lens and the second single-sided convex lens is obtained by twisting the equation (1) according to the shortest focal length, the longest focal length, the light transmittance, and the refractive index of the material, and the expression is:

Where Z _c is the central focal length, Z ₀ is twice the central focal length, and the intermediate variable function

Z ₀ = 2Z _c , the expression of the variable x is:

The radial angle of the lens;

S105. Construct a derivation according to the distortion-converted focal length function to obtain a radial derivative function of the first single-sided convex lens and the second single-sided convex lens. The expression of the radial derivative function is:

Simplified to get:

Where f is the focal length value, ie the focal length function F(), ω is the refractive index, and r is the distance from the point on the curved surface to the center of the circle;

S106. Integrating a radial derivative function to obtain a surface surface equation of the first single-sided convex lens and the second single-sided convex lens;

Where f is the focal length value, ie the focal length function F(), ω is the refractive index, m is the distance from the point on the curved surface to the center of the lens, and r is the distance from the point on the curved surface to the center of the circle.

S107. Convert the first single-sided convex lens and the second single-sided convex lens into a Fresnel lens. According to the pitch required by the system, the first single-sided convex lens is divided into a concentric circle by the center of the first single-sided convex lens, and the first single-sided convex lens surface is divided. For two or more annular regions, the center of the second single-sided convex lens is a concentric circle, and the second single-sided convex lens surface is divided into two or more annular regions, a first single-sided convex lens and a second single-sided lens. The annular area defined by the convex lens is the same, and the surface surface equation obtained by converting the first single-sided convex lens and the second single-sided convex lens into a Fresnel lens is obtained, and the expression is:

Where τ is the Fresnel lens pitch, f is the focal length value, ω is the refractive index, m is the distance from the point on the curved surface to the center of the lens, r is the distance from the point on the curved surface to the center of the circle,

Substituting S(f,ω,m)

The lens thickness of the Fresnel lens is changed according to the polar diameter. The polar diameter is a related concept of polar coordinates. The distance from a certain point to the pole in the polar coordinate plane is the polar diameter.

When converting the first single-sided convex lens and the second single-sided convex lens into a Fresnel lens, the method adopted by the present invention is a radial halving cutting method to ensure that the dividing line of the cutting must be a concentric circle, so that the plurality of lenses are opposite. When rotating, their respective annular regions are always opposite, and a schematic diagram of the cutting method thereof can be referred to FIG. Converting the first single-sided convex lens and the second single-sided convex lens into a Fresnel lens can make the lens thinner, so that the lens system has better optical performance, and at the same time contributes to miniaturization of the lens system.

S108. The respective annular regions of the first single-sided convex lens are rotated and staggered, and the annular regions of the second single-sided convex lens are rotated and staggered, and the first single-convex lens and the second single-convex lens are rotated to be the same. By shifting the respective annular regions of the first single-convex lens and the single-sided convex lens, the uniformity of light entering can be increased.

S109. Perform optical path verification on the designed first single-sided convex lens, and the empirical calculation steps are as follows:

Substituting ζ and r of different values into the optical path verification formula to verify whether the calculation result is within the set error range, and the expression of the optical path verification formula is:

Where x is the x-axis coordinate of the point, f is the focal length value, ie the focal length function F(), ω is the refractive index, r is the distance from the point to the center of the surface, and ζ is the angle between the incident ray and the y-axis, the lens A radial direction is the x-axis and the main optical axis of the lens is the y-axis.

The step S2 includes:

S201. Taking the center of the first uniplanar convex lens as a pole, the ideal occlusion area of the liquid crystal module 3 in the cylindrical coordinates is:

among them,

For the radial angle of the lens, θ is the first single-sided convex lens and the second single-sided convex lens

The angle between the points, m is the distance from the point on the curved surface to the center of the lens, m ₂ is the radius of the second single-sided convex lens, τ is the pitch, μ is a positive integer, and φ is a radial angle value function.

The position of the specific occlusion of the occlusion region is related to the relative rotation angle θ of the first unilateral convex lens and the second unilateral convex lens.

S202, by increasing the occlusion area by expanding the edge ι, after the area is increased, the ideal occlusion area in the column coordinates of the liquid crystal module 3 (any element belonging to the set is included in the occlusion area) is:

Where ι is the extended length, and θ is the first single-sided convex lens and the second single-sided convex lens

The angle at which ε is used to exhaust the count value associated with ι.

The above is a detailed description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the invention. Such equivalent modifications or substitutions are intended to be included within the scope of the appended claims.

Claims

A rotary zoom lens system, comprising: a first lens group, a second lens group, and a liquid crystal module, wherein an optical axis of the first lens group and an optical axis of the second lens group are on a same line, the The focal length of the superimposed lens group and the second lens group is changed as the relative angles of the first lens group and the second lens group are changed, and the liquid crystal module is mounted on one side of the first lens group or one of the second lens groups. side.
A rotary zoom lens system according to claim 1, wherein said first lens group and said second lens group each include at least one lens, and a focal length of said lens changes as a radial angle changes.
A rotary zoom lens system according to claim 2, wherein said first lens group comprises a first single-sided convex lens, said second lens group comprises a second single-sided convex lens, said first single side The convex lens is the same as the second single-sided convex lens, and the plane of the first single-sided convex lens is opposite to the plane of the second single-sided convex lens, and the liquid crystal module is mounted between the first single-convex lens and the second single-sided convex lens.
A rotary zoom lens system according to claim 3, wherein the cylindrical coordinate surface equation of the first single-sided convex lens is:

Where f is the focal length value, ω is the refractive index, m is the distance from the point on the curved surface to the center of the lens, and r is the distance from the point on the curved surface to the center of the circle.
A rotary zoom lens system according to claim 4, wherein said first single-sided convex lens is a Fresnel lens, and a cylindrical coordinate surface surface equation of said Fresnel lens is:

Where τ is the Fresnel lens pitch,
The amount of lens thickness cut as a function of the polar diameter produced by Fresnel lensing.
A method for implementing a rotary zoom lens system according to any one of claims 1 to 5, comprising the steps of:

Calculating a surface surface equation of a lens in the first lens group and a lens in the second lens group;

Calculating an occlusion region of the liquid crystal module according to a surface curvature equation of the lens in the first lens group and the lens in the second lens group;

The rotary zoom lens system is obtained based on the surface curved surface equation of the lens in the first lens group, the surface curved surface equation of the lens in the second lens group, and the occlusion region of the liquid crystal module.
The method for realizing a rotary zoom lens system according to claim 6, wherein the lens in the first lens group is a first single-sided convex lens, and the lens in the second lens group is a first A two-sided convex lens, the first single-sided convex lens and the second single-sided convex lens being the same.
The method for realizing a rotary zoom lens system according to claim 7, wherein the calculating the surface surface equation of the lens in the first lens group and the lens in the second lens group includes :

Enter the shortest focal length, the longest focal length, the light transmittance, and the refractive index of the material of the rotating zoom lens system;

According to the focal length superposition theorem, a composite focal length function of the first single-sided convex lens and the second single-sided convex lens in a Cartesian coordinate system is obtained, and the expression of the synthetic focal length function is:

Ω(f 1 ,f 2 )=(f 1 *f 2 )/(f 1 +f 2 );

Wherein f 1 is a focal length of the first single-sided convex lens, and f 2 is a focal length of the second single-sided convex lens;

Performing a distortion transformation on the composite focal length function in the Cartesian coordinate system according to the shortest focal length, the longest focal length, the light transmittance, and the refractive index of the material to obtain a focal length function after the distortion transformation of the first single convex lens and the second single convex lens, The expression of the twisted transformed focal length function is:

Where Z 0 = 2Z c , Z c is the central focal length, Z 0 is twice the central focal length, intermediate variable function
The expression for the intermediate variable x is:

Where v H is the maximum value of the intermediate variable x, v L is the minimum value of the intermediate variable x, x ∈ (v L , v H ),
Radial angle

A radial derivative function of the first single-sided convex lens and the second single-sided convex lens is obtained according to the focal length function after the distortion transformation, and the expression of the radial derivative function is:

Where f is the focal length value, ω is the refractive index, and r is the distance from the point on the curved surface to the center of the circle;

Integrating the obtained radial derivative function to obtain a surface surface equation of the first single-sided convex lens and the second single-sided convex lens, and the expressions of the surface surface equations of the first single-sided convex lens and the second single-sided convex lens are:

Where m is the distance from the point on the surface to the center of the lens.
The method for realizing a rotary zoom lens system according to claim 8, wherein the step of calculating a surface curvature equation of the lens in the first lens group and the lens in the second lens group is further The method comprises: converting the first single-convex lens and the second single-convex lens into a Fresnel lens, and the surface surface equation after the first single-sided convex lens and the second single-sided convex lens are converted into a Fresnel lens is:

Where τ is the pitch of the Fresnel lens,
The amount of lens thickness cut as a function of the polar diameter produced by Fresnel lensing.
The method for realizing a rotary zoom lens system according to claim 9, wherein the expression of the occlusion region of the liquid crystal module in polar coordinates is:

among them,
For the radial angle of the lens, m is the distance from the point on the curved surface to the center of the lens, m 2 is the radius of the second single-sided convex lens, τ is the pitch, φ() is the function of the radial angle, and μ is a positive integer. , ι is the extended length, ε is the count value used for exhaustive and ι, and θ is the first single-sided convex lens and the second single-sided convex lens
The angle of the place.