WO2022121173A1 - 一种应用形变器件的高变倍比不动变焦成像方法 - Google Patents
一种应用形变器件的高变倍比不动变焦成像方法 Download PDFInfo
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- the invention relates to the technical field of optical zoom, in particular to a high-variable-ratio fixed zoom imaging method using a deformable device.
- Zoom systems play an indispensable role in many fields, such as biomedical fields, security monitoring fields, and national defense construction fields.
- the traditional component mobile zoom method can realize the optical system with high zoom ratio and high imaging quality, it has disadvantages such as difficulty in miniaturization and slow zoom speed, which limits its application in emerging fields such as intelligent robots and unmanned aerial vehicles.
- the new fixed zoom system uses variable power elements to realize the zoom function, such as liquid lenses and deformable mirrors and other deformable devices.
- This new type of zoom system does not require moving optical components, so there is no need for mechanical structures such as cam mechanisms.
- the characteristics of miniaturization, fast zoom and low energy consumption have gradually become the research and application hotspot in the field of optical zoom.
- the present invention proposes a high-variable-ratio fixed zoom imaging method using a deformable device, which can realize high-variable-ratio fixed zoom imaging under the condition of limited high-precision deformation range of the deformable device.
- the invention discloses a high-variable-ratio fixed zoom imaging method using a deformable device, comprising the following steps:
- S3 A nonlinear global evaluation function is established in combination with the key parameters and the first-order aberration parameters, and a fixed zoom system with a high zoom ratio is obtained by retrieving the optimal solution of the nonlinear global evaluation function.
- the key parameters in step S1 include: the equivalent focal length of the fixed zoom system and the error term of the defocus amount of the system.
- the first-order aberration parameters of the fixed zoom system in step S2 include the error terms of the first-order spherical aberration, the first-order astigmatism and the first-order distortion of the fixed zoom system.
- step S3 a global optimization algorithm is used to retrieve the global optimal solution of the nonlinear global evaluation function, and the solution set with the smallest numerical value of the nonlinear global evaluation function is obtained, and a solution set with the highest numerical value is obtained according to the solution set.
- Fixed zoom system with zoom ratio is used to retrieve the global optimal solution of the nonlinear global evaluation function, and the solution set with the smallest numerical value of the nonlinear global evaluation function is obtained, and a solution set with the highest numerical value is obtained according to the solution set.
- the beneficial effects of the present invention are: the high-variable-ratio non-moving zoom imaging method using a deformable device proposed by the present invention takes a novel non-moving zoom system as a model, and uses Gaussian bracket method and vector aberration respectively.
- Theoretical analysis of the Gaussian solution characteristics of the zoom equation and the first-order aberration characteristics of the new zoom system, and a global evaluation function that can comprehensively evaluate the zoom capability and imaging quality of the zoom system are constructed.
- the global evaluation function retrieves the optimal solution problem, automatically retrieves the optimal Gaussian structure of the new fixed zoom system, and then realizes high zoom ratio fixed zoom imaging under the condition of limited high-precision deformation range of the deformable device.
- Fig. 1 is the flow chart of the high variable magnification ratio fixed zoom imaging method of the application of the deformation device proposed by the preferred embodiment of the present invention
- Fig. 2 is the paraxial ray tracing model diagram of the fixed zoom system of the specific example of the present invention
- Fig. 3 is the real ray tracing model diagram of the optical system based on three optical component plane symmetry of the specific example of the present invention
- FIG. 4 is a design flow chart of a fixed zoom system of a specific example of the present invention.
- the new fixed zoom system has good application prospects, but due to the limited high-precision deformation of deformable devices such as liquid lenses and deformable mirrors, the zoom systems obtained by the existing new fixed zoom design methods are difficult to achieve high zoom ratios . Therefore, how to achieve a high zoom ratio within the high-precision deformation range of deformable mirrors and other deformable devices is of great significance to the development and application of new zoom systems.
- a preferred embodiment of the present invention proposes a high-variable-ratio fixed zoom imaging method using a deformable device, which includes the following steps:
- S1 Use the Gauss bracket method to establish a zoom equation of a fixed zoom system including a deformable device, and extract key parameters that can determine the zoom ratio of the fixed zoom system according to the zoom equation; wherein, the key parameters include: the fixed zoom system The error term of the equivalent focal length and the system defocus amount.
- S2 Calculate the first-order aberration parameters of the fixed zoom system according to the vector aberration theory and the Seidel aberration coefficient; wherein, the first-order aberration parameters of the fixed zoom system include: the first-order spherical aberration of the fixed zoom system, Error terms for primary astigmatism and primary distortion.
- S3 Combine key parameters and primary aberration parameters to establish a nonlinear global evaluation function, and obtain a fixed zoom system with a high zoom ratio by retrieving the optimal solution of the nonlinear global evaluation function.
- the zoom equation of the new fixed zoom system is analyzed by using the Gauss bracket method, the key parameters that can determine the zoom ratio of the fixed zoom system are extracted, and the key parameters and the The optical power changing ability of the deformable device is related; (2) the vector aberration theory is introduced, combined with the Seidel aberration coefficient, the first-order aberration coefficient of the new fixed zoom system is analytically characterized, and the first-order aberration coefficient is directly introduced in the system design stage.
- Aberration evaluation 3.
- a nonlinear global evaluation function that can comprehensively evaluate the imaging performance and zooming ability of the new fixed zoom system is established. Directly obtain a high zoom ratio fixed zoom system with good imaging quality.
- the system consists of n optical elements (in this specific example, the surface type of the optical element is a quadratic aspheric surface), of which the mth and nth elements are variable optical power elements, that is, deformable devices, such as liquids. lens or deformable mirror.
- the 1st to m-1th optical elements are equivalently regarded as an optical component with a refractive power of ⁇ pre .
- the m+1th to n-1th optical elements are regarded as Equivalently, it is regarded as an optical component with a refractive power of ⁇ mid .
- n i represents the refractive index after the ith optical element
- e' 0 , e' 1 , e' 2 and e' 3 are the equivalent intervals between two adjacent optical components
- e' 4 en is The rear working focal length of this zoom system.
- the new fixed zoom equation Z can be obtained as:
- h j is the edge ray height of the jth optical element
- hi is the edge ray height of the ith optical element
- ui is the edge ray incident angle of the ith optical element
- u' j is the jth optical element.
- the optical power of the deformation device can be expressed as:
- Equations (6) and (7) are monotonic functions, and equations (4) and (5) are combined together.
- the working focal length after the system is equivalent can be expressed as:
- the scalars A foc and A def are the error terms representing the equivalent focal length of the zoom system and the amount of defocusing of the system; f represents the equivalent focal length of the system; ⁇ represents the zoom ratio of the system; ⁇ L represents the light of the zoom system at telephoto Power; ⁇ m and ⁇ n represent the change of the power of the two deformable devices, respectively.
- the system parameter variables of the new fixed zoom system are only the surface parameters of the deformable device. Therefore, the system model makes the following constraints.
- OAR optical axis ray
- the system model makes the following constraints.
- OAR optical axis ray
- the aspherical portion of the optic surface shape will not contribute to the normalized field of view vector of the system.
- the off-axis optical system we design by convention is symmetric about the yoz plane. Therefore, the spherical portion of the optic surface shape will not cause an x-direction shift to the normalized field of view vector of the system. Finally, based on the ray tracing of the fixed OAR of the fixed zoom system, the field of view offset vector of the system can be directly calculated.
- the real ray tracing model taking the three-component plane symmetric optical system as an example is shown in Figure 3.
- o j represents the vertex of the j-th optical element surface
- S j represents the optical surface of the j-th optical element
- the angle of inclination ⁇ j is equal to the OAR incident angle and is also the same as the vector The angle is equal to that of the OAR.
- Equation (14) the tilt angle ⁇ j of the j-th optical element of the system can be expressed by Equation (14).
- the field of view offset vector of the system can be expressed as:
- c j represents the vertex curvature of the jth optical element surface.
- the parameters that characterize the primary aberration of the system can be obtained analytically.
- the first-order spherical aberration coefficient of the off-axis system can be expressed as
- the scalar A spa is the error term characterizing the primary spherical aberration of the zoom system;
- W 040j represents the primary spherical aberration coefficient of the jth optical element of the coaxial system;
- S Ij represents the first Seidel image of the jth optical element of the coaxial system Difference coefficient, superscript sph and asph represent spherical and aspheric surfaces, respectively;
- h j represents the edge ray height of the jth optical element, u j and u' j represent the edge ray incident angle and exit angle of the jth optical element, respectively;
- a j (u' j -u j )/(1/n j+1 -1/n j );
- c j represents the vertex curvature of the j-th optical element surface,
- k j represents the j-th optical element surface
- the quadric constant of , n j represents the refractive index after the jth optical
- the first-order astigmatism coefficient of the off-axis system can be expressed as
- the vector A ast is the error term characterizing the primary astigmatism of the zoom system
- W 222j represents the primary astigmatic coefficient of the jth optical element of the coaxial system
- S IIIj represents the third Seidel aberration coefficient of the jth optical element of the on-axis system, and the superscripts sph and asph represent spherical and aspheric surfaces, respectively
- h j represents the edge ray height of the jth optical element, represents the central ray height of the jth optical element
- u j and u' j represent the edge ray incident angle and exit angle of the jth optical element, respectively, and Respectively represent the central ray incident angle and exit angle of the jth optical element
- c j represents the vertex curvature of the jth optical element surface
- k j represents the quadratic surface parameter of the jth optical element surface
- the first-order distortion coefficient of the off-axis system can be expressed as
- the vector A dis is the error term characterizing the primary distortion of the zoom system
- W 311j represents the primary distortion coefficient of the jth optical element of the coaxial system
- S Vj represents the fifth Seidel aberration coefficient of the jth optical element in the on-axis system, the superscript sph and asph represent spherical and aspheric surfaces, respectively
- h j represents The marginal ray height of the jth optic, represents the central ray height of the jth optical element, u j and u' j represent the edge ray incident angle and exit angle of the jth optical element, respectively, and represent the central ray incident angle and exit angle of the jth optical element, respectively;
- c j represents the vertex curvature of the surface shape of the jth optical element
- k j represents the quadratic surface parameter of the surface shape of the jth optical element
- n j represents
- the primary aberration of the zoom system the zoom capability of the system (such as zoom ratio), and the Gaussian characteristics of the system (such as the fixed back focal length of the zoom system) will be used as comprehensive evaluation indicators.
- the nonlinear global evaluation function is specifically expressed as follows:
- the superscript l represents the lth sampling focal length point of the zoom system; M represents the number of sampling focal length points; H k represents the kth sampling field of view point, N represents the number of sampling field of view points; e j represents the jth field of view and the equivalent spacing between the j+1 th optical element, ⁇ j represents the tilt angle of the j th optical element, c i , cm and cn represent the i th, mth and nth optical elements, respectively.
- 1 means 1 norm.
- A1 Determine the structural requirements of the zoom system: including the number of surfaces, the position of the aperture stop and the pupil aperture, etc.;
- A2 Determine the zoom requirements of the zoom system: including the zoom ratio of the zoom system, the change range of the optical power of the deformable device, etc.;
- A3 Fast coaxial system paraxial ray tracing based on Gaussian bracket method
- A4 According to the derivation result of the zoom equation of the fixed zoom system, extract the law of the solution that meets the zoom performance requirements of the zoom system: including the value of the working focal length after the system, etc.;
- A5 Based on the vector aberration theory, calculate the first-order pixel coefficients of the off-axis system: including spherical aberration, astigmatism and distortion, etc.;
- A6 Establish a global evaluation function of the off-axis fixed zoom system: the evaluation index consists of the imaging quality and zoom capability of the zoom system;
- A7 Use the global optimization algorithm to retrieve the optimal solution of the evaluation function
- step A8 Determine whether the optimization termination condition is satisfied, if so, execute step A9, if not, return to step A7;
- A9 Convert the optimal solution data obtained by retrieval into Gaussian structure parameters of the zoom system
- A10 Using optical design software, only the surface parameters of the Gaussian structure are optimized under the premise that the other system parameters remain unchanged;
- A11 Output the final fixed zoom system Gaussian structure parameters.
- High zoom ratio By analyzing the zoom equation of the new fixed zoom system, and taking the power changing capabilities ⁇ m and ⁇ n of the deformable device as constraints, the key parameters that can determine the zoom ratio of the zoom system are extracted. and Then, the deformation performance of the deformation device is maximized to realize the high zoom ratio of the new fixed zoom system.
- Performance regulation This design method not only characterizes the zoom capability of the new fixed zoom system, but also uses the three parameters A spa , A ast and A dis to analytically characterize the system's primary aberration characteristics; by controlling the nonlinear
- the weight of each error term of the global evaluation function can meet the specific performance requirements of the zoom system (such as sacrificing the imaging performance under the short-focus working condition of the system, and realizing the high resolution under the long-focus working condition of the system, etc.).
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Abstract
一种应用形变器件的高变倍比不动变焦成像方法，包括以下步骤：S1：采用高斯括号法建立包含形变器件的不动变焦系统的变焦方程，根据变焦方程提取出能够决定不动变焦系统的变倍比的关键参数；S2：根据矢量像差理论和赛德尔像差系数，计算不动变焦系统的初阶像差参数；S3：结合关键参数和初阶像差参数建立非线性全局评价函数，通过对非线性全局评价函数进行最优解检索，获得具有高变倍比的不动变焦系统。应用形变器件的高变倍比不动变焦成像方法能够在形变器件高精度形变范围有限的条件下实现高变倍比不动变焦成像。
Description
本发明涉及光学变焦技术领域，尤其涉及一种应用形变器件的高变倍比不动变焦成像方法。
变焦系统在很多领域都发挥着不可或缺的作用，如生物医学领域、安防监控领域以及国防建设领域等。传统的组元移动式变焦方式虽然可以实现高变倍比、高成像质量的光学系统，但是具有小型化困难和变焦速度慢等缺点，这限制了它在智能机器人、无人机等新兴领域的应用。新型的不动变焦系统采用光焦度可变元件来实现变焦功能，比如液体透镜和可变形镜等形变器件，此类新型变焦系统不需要移动光学组元，因此无需凸轮机构等机械结构，具有小型化、快速变焦和能耗低等特点，逐渐成为了光学变焦领域的研究与应用热点。
目前常用的光学变焦系统设计方法主要有两种：①直接计算系统高斯结构，如PW法、Lens module求解法等；②检索功能相似的光学系统专利，主要为缩放法等。然而，对于新型不动变焦系统这类复杂光学系统，直接计算系统的高斯结构非常困难，计算过程繁琐耗时，设计效率极其低下。此外，新型变焦系统还处于发展阶段，相关专利类型和数量都非常有限，采用缩放法设计也并不适用。综上，虽然新型的不动变焦系统具有上述优点，但是大多都还存在难以实现高变倍比的问题。
以上背景技术内容的公开仅用于辅助理解本发明的构思及技术方案，其并不必然属于本专利申请的现有技术，在没有明确的证据表明上述内容在本专利申请的申请日已经公开的情况下，上述背景技术不应当用于评价本申请的新颖性和创造性。
发明内容
为解决上述技术问题，本发明提出一种应用形变器件的高变倍比不动变焦成 像方法，能够在形变器件高精度形变范围有限的条件下实现高变倍比不动变焦成像。
为了达到上述目的，本发明采用以下技术方案：
本发明公开了一种应用形变器件的高变倍比不动变焦成像方法，包括以下步骤：
S1：采用高斯括号法建立包含形变器件的不动变焦系统的变焦方程，根据所述变焦方程提取出能够决定所述不动变焦系统的变倍比的关键参数；
S2：根据矢量像差理论和赛德尔像差系数，计算所述不动变焦系统的初阶像差参数；
S3：结合所述关键参参数和所述初阶像差参数建立非线性全局评价函数，通过对所述非线性全局评价函数进行最优解检索，获得具有高变倍比的不动变焦系统。
优选地，步骤S1中的所述关键参数包括：所述不动变焦系统的等效焦距和系统离焦量的误差项。
优选地，步骤S2中的所述不动变焦系统的初阶像差参数包括所述不动变焦系统的初阶球差、初阶像散和初阶畸变的误差项。
优选地，步骤S3中采用全局优化算法来对所述非线性全局评价函数进行全局最优解检索，求解得到另所述非线性全局评价函数的数值最小的解集，根据该解集获得具有高变倍比的不动变焦系统。
与现有技术相比，本发明的有益效果在于：本发明提出的应用形变器件的高变倍比不动变焦成像方法，以新型不动变焦系统为模型，分别运用高斯括号法和矢量像差理论分析该新型变焦系统的变焦方程高斯解特性和初阶像差特性，构建一个可以综合评价变焦系统变焦能力和成像质量的全局评价函数，将新型变焦系统的高斯结构设计问题转化为利用非线性全局评价函数检索最优解问题，自动检索新型不动变焦系统的最优高斯结构，进而在形变器件高精度形变范围有限的条件下实现高变倍比不动变焦成像。
图1是本发明优选实施例提出的应用形变器件的高变倍比不动变焦成像方 法的流程图；
图2是本发明具体实例的不动变焦系统的近轴光线追迹模型图；
图3是本发明具体实例的基于三个光学组元面对称的光学系统的真实光线追迹模型图；
图4是本发明具体实例的不动变焦系统的设计流程图。
下面对照附图并结合优选的实施方式对本发明作进一步说明。
新型不动变焦系统具有良好的应用前景，但是由于液体透镜和可变形镜等形变器件的高精度形变量受限，已有的新型不动变焦设计方法得到的变焦系统皆难以实现高变倍比。因此，如何在可变形镜等形变器件的高精度形变范围内实现高变倍比，对新型变焦系统的发展和应用具有重大意义。
如图1所示，本发明优选实施例提出一种应用形变器件的高变倍比不动变焦成像方法，包括以下步骤：
S1：采用高斯括号法建立包含形变器件的不动变焦系统的变焦方程，根据所述变焦方程提取出能够决定不动变焦系统的变倍比的关键参数；其中，关键参数包括：不动变焦系统的等效焦距和系统离焦量的误差项。
S2：根据矢量像差理论和赛德尔像差系数，计算不动变焦系统的初阶像差参数；其中，不动变焦系统的初阶像差参数包括：不动变焦系统的初阶球差、初阶像散和初阶畸变的误差项。
S3：结合关键参参数和初阶像差参数建立非线性全局评价函数，通过对非线性全局评价函数进行最优解检索，获得具有高变倍比的不动变焦系统。
本发明优选实施例中主要有三个关键点：①运用高斯括号法分析了新型不动变焦系统的变焦方程，提取出了能够决定不动变焦系统变倍比的关键参数，并且将该关键参数和形变器件的光焦度变化能力关联起来；②引入矢量像差理论，结合塞德尔像差系数，解析地表征了新型不动变焦系统的初阶像差系数，在系统设计阶段直接引入了初阶像差评价；③建立了能够综合评价新型不动变焦系统的成像性能和变焦能力的非线性全局评价函数，通过运用全局优化算法(如遗传算法)对该评价函数进行全局最优解检索，可以直接获得具有良好成像质量的高变倍比 不动变焦系统。
下述结合具体实例对本发明优选实施例提出的应用形变器件的高变倍比不动变焦成像方法进行进一步说明。
该具体实例的实现方法如下：
1)如图2所示，建立采用二次非球面的包含两个形变器件的多组元不动变焦系统模型，并基于该模型构建新型不动变焦方程，分析其高斯解特性。
该系统由n个光学元件(本具体实例中，光学元件面型为二次非球面)组成，其中第m个和第n个是光焦度可变元件，也即形变器件，例如可以是液体透镜或可变形镜。如图2所示，将第1至第m-1个光学元件等效的视为一个光焦度为φ
pre的光学组元，同理，将第m+1至第n-1个光学元件等效的视为一个光焦度为φ
mid的光学组元。n
i表示第i个光学元件后的折射率，e'
0，e'
1，e'
2和e'
3则是相邻两光学组元之间的等效间隔，e'
4＝e
n是该变焦系统的后工作焦距。定义φ
i(i＝1,2,3,…)为光学系统不同组元的光焦度，e
i(i＝1,2,3,…)为光学系统组元i和组元i+1之间的等效间隔。为了描述光学系统第i个组元到第j个组元的的一阶特性，定义四个高斯常量(Generalized Gaussian Constants,GGC’s)，分别用
iA
j，
iB
j，
iC
j和
iD
j表示，它们的表达式如下：
运用高斯括号法分析图2所示多组元不动变焦系统模型，可得新型不动变焦方程Z为：
系统等效光焦度Φ为：
高斯括号法的运算法则和近轴追迹公式如下：
其中，h
j为第j个光学元件的边缘光线高度，h
i为第i个光学元件的边缘光线高度；u
i为第i个光学元件的边缘光线入射角，u'
j为第j个光学元件的边缘光线出射角。
根据式(2)、(3)，形变器件的光焦度可表示为：
式(6)、(7)是单调函数，联立式(4)、(5)，系统等效后工作焦距可表示为：
综上，联立式(3)、(8)和(9)，可提取出决定变焦系统变焦能力的关键参数如下：
其中，标量A
foc和A
def分别为表征变焦系统等效焦距和系统离焦量的误差项；f表示系统等效焦距；Γ表示系统变倍比；Φ
L表示变焦系统在长焦时的光焦度；Δφ
m和Δφ
n分别表示两个形变器件的光焦度变化量。
2)根据矢量像差理论，分析上述新型不动变焦系统模型，离轴光学系统第j个光学元件的等效视场
如式(12)所示。本实例的像差理论分析以离轴光学系统为例，但也适用于同轴光学系统(即视场偏移矢量为零)。
其中，
表示归一化的视场向量，
表示第j个光学元件的视场偏移矢量。
新型不动变焦系统的系统参数变量只有形变器件的面形参数，因此，系统模型作出以下约束条件。首先，定义系统的光轴光线(optical axis ray，OAR)即系统零视场点的中心光线，为保证变焦系统在变焦过程中OAR是固定不变的，在系统的设计过程中，只采用倾斜表面以及视场中心偏移的方法来实现无遮挡的系统离轴。这一约束条件对于新型不动变焦系统各光学元件以及像方平面位置的稳定非常重要。此外，光学元件面形的非球面部分将不会对系统的归一化视场向量造成影响。其次，我们约定设计的离轴光学系统是关于yoz面对称的。因此，光学元件面形的球面部分将不会对系统的归一化视场向量造成x方向的偏移。最后，基于不动变焦系统固定OAR的光线追迹，可以直接计算得到系统的视场偏移向量
以三组元面对称光学系统为例的真实光线追迹模型如图3所示。其中，
表示第j个光学元件光学表面的单位法矢量，o
j表示第j个光学元件面形的顶点，S
j表示第j个光学元件的光学表面，第j个光学元件面形顶点o
j处的倾斜角α
j与OAR入射角相等，也与矢量
和OAR的夹角相等。
基于每个系统光学元件的OAR局部坐标，图3的矢量
可以由式(13)表示。
其中，SRM
j和SRN
j分别表示矢量
沿着y和z方向的归一化方向余弦。因此，系统第j个光学元件的倾斜角α
j可以由式(14)表示。
α
j＝arcsin(SRM
j) (14)
因此，系统的视场偏移矢量可以表示为：
其中，
表示第j个光学元件在y方向的视场偏移矢量；
表示第j个光 学元件的边缘光线出射角；
表示第j个光学元件的中心光线高度；c
j表示第j个光学元件面形的顶点曲率。
结合同轴系统赛德尔像差系数，可解析得到表征系统初阶像差的参数。
①初阶球差
根据矢量像差理论，离轴系统的初阶球差系数可以表示为
其中，
标量A
spa为表征变焦系统初阶球差的误差项；W
040j表示同轴系统第j个光学元件的初阶球差系数；S
Ⅰj表示同轴系统第j个光学元件的第一赛德尔像差系数，上标sph和asph分别表示球面和非球面；h
j表示第j个光学元件的边缘光线高度，u
j和u'
j分别表示第j个光学元件的边缘光线入射角和出射角；A
j＝(u'
j-u
j)/(1/n
j+1-1/n
j)；c
j表示第j个光学元件面形的顶点曲率，k
j表示第j个光学元件面形的二次曲面常数，n
j表示第j个光学元件后的折射率。
②初阶像散
根据矢量像差理论，离轴系统的初阶像散系数可以表示为
其中，
矢量A
ast为表征变焦系统初阶像散的误差项；W
222j表示同轴系统第j个光学元件的初阶像散系数；
表示离轴系统第j个光学元件的等效视场；S
Ⅲj表示 同轴系统第j个光学元件的第三赛德尔像差系数，上标sph和asph分别表示球面和非球面；
h
j表示第j个光学元件的边缘光线高度，
表示第j个光学元件的中心光线高度，u
j和u'
j分别表示第j个光学元件的边缘光线入射角和出射角，
和
分别表示第j个光学元件的中心光线入射角和出射角；c
j表示第j个光学元件面形的顶点曲率，k
j表示第j个光学元件面形的二次曲面参数，n
j表示第j个光学元件后的折射率。
③初阶畸变
根据矢量像差理论，离轴系统的初阶畸变系数可以表示为
其中，
矢量A
dis为表征变焦系统初阶畸变的误差项；W
311j表示同轴系统第j个光学元件的初阶畸变系数；
表示离轴系统第j个光学元件的等效视场；S
Ⅴj表示同轴系统第j个光学元件的第五赛德尔像差系数，上标sph和asph分别表示球面和非球面；h
j表示第j个光学元件的边缘光线高度，
表示第j个光学元件的中心光线高度，u
j和u'
j分别表示第j个光学元件的边缘光线入射角和出射角，
和
分别表示第j个光学元件的中心光线入射角和出射角；
c
j表示第j个光学元件面形的顶点曲率，k
j表示第j个光学元件面形的二次曲面参数，n
j表示第j个光学元件后的折射率。
3)结合上述变焦方程分析和变焦系统初阶像差分析，运用新型不动变焦系 统变焦过程中的系统参数变量和不变量，建立一个可以直接综合评价变焦系统在工作焦距范围内的成像性能和变焦能力的非线性全局评价函数L。
其中，变焦系统的初阶像差、系统的变焦能力(如变倍比)以及系统的高斯特性(如变焦系统固定的后焦距)都将作为综合评价指标。该非线性全局评价函数具体表示如下：
其中，上标l表示变焦系统的第l个采样焦距点；M表示采样焦距点的数量；H
k表示第k个采样视场点，N表示采样视场点的数量；e
j表示第j个和第j+1个光学元件之间的等效间隔，α
j表示第j个光学元件的倾斜角，c
i、c
m和c
n分别表示第i个、第m个和第n个光学元件面形的顶点曲率；k
i、k
m和k
n分别表示第i个、第m个和第n个光学元件面形的二次曲面参数；ν
i(i＝1,2,3,…)表示对应项的权重；
||||
1表示1范数。
运用全局优化算法(如遗传算法)来检索满足设计需求的系统最优高斯结构，即求解令评价函数式(25)数值最小的解集，主要步骤如图4所示，包括：
A1：确定变焦系统的结构需求：包括面形数量，孔径光阑位置和光瞳孔径等；
A2：确定变焦系统的变焦需求：包括变焦系统的变倍比，形变器件的光焦度变化范围等；
A3：基于高斯括号法的快速同轴系统近轴光线追迹；
A4：根据不动变焦系统的变焦方程推导结果，提取满足变焦系统变焦性能要求的解的规律：包括系统后工作焦距的数值等；
A5：基于矢量像差理论，计算离轴系统的初阶像素系数：包括球差、像散和畸变等；
A6：建立离轴不动型变焦系统全局评价函数：评价指标由变焦系统的成像质量和变焦能力组成；
A7：利用全局优化算法对评价函数进行最优解检索；
A8：判断优化终止条件是否满足，如果是，则执行步骤A9，如果否，则返回步骤A7；
A9：将检索得到的最优解数据转换成变焦系统高斯结构参数；
A10：运用光学设计软件，在其余系统参数不变的前提下，仅对该高斯结构的面形参数进行优化；
A11：输出最终的不动变焦系统高斯结构参数。
采用本发明具体实例的新型不动变焦系统设计方法，具有以下三个优点：
(1)高变倍比；通过分析新型不动变焦系统的变焦方程，并将形变器件的光焦度变化能力Δφ
m和Δφ
n作为约束条件，提取出能够决定变焦系统变倍比的关键参数
和
进而最大化地运用形变器件的变形性能，实现新型不动变焦系统的高变倍比。
(2)高效设计：建立了能同时评价新型变焦系统成像性能和变焦能力的非线性全局评价函数L，将系统高斯结构设计问题转化为利用非线性全局评价函数L检索最优解问题，进而实现了新型不动变焦系统最优高斯结构的自动检索，极大地提高了此类复杂光学系统的设计效率。
(3)性能调控：本设计方法不仅表征了新型不动变焦系统的变焦能力，还运用A
spa、A
ast和A
dis三个参数解析地表征了系统的初阶像差特性；通过控制非线性全局评价函数各误差项的权重，可以实现特定的变焦系统性能需求(如牺牲系统短焦工况下的成像性能，实现系统长焦工况的高分辨率等)。
以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明，不能认定本发明的具体实施只局限于这些说明。对于本发明所属技术领域的技术人员来说，在不脱离本发明构思的前提下，还可以做出若干等同替代或明显变型，而且性能或用途相同，都应当视为属于本发明的保护范围。
Claims (10)
- 一种应用形变器件的高变倍比不动变焦成像方法，其特征在于，包括以下步骤：S1：采用高斯括号法建立包含形变器件的不动变焦系统的变焦方程，根据所述变焦方程提取出能够决定所述不动变焦系统的变倍比的关键参数；S2：根据矢量像差理论和赛德尔像差系数，计算所述不动变焦系统的初阶像差参数；S3：结合所述关键参参数和所述初阶像差参数建立非线性全局评价函数，通过对所述非线性全局评价函数进行最优解检索，获得具有高变倍比的不动变焦系统。
- 根据权利要求1所述的高变倍比不动变焦成像方法，其特征在于，步骤S1中的所述关键参数包括：所述不动变焦系统的等效焦距和系统离焦量的误差项。
- 根据权利要求1所述的高变倍比不动变焦成像方法，其特征在于，步骤S1中采用高斯括号法建立的包含形变器件的不动变焦系统的变焦方程Z为：Z＝[φ 1,-e 1,…,φ m,-e m,…,φ n,-e n]＝[φ pre,-e' 1,φ m,-e' 2,φ mid,-e' 3,φ n,-e' 4]＝0其中，φ i(i＝1,2,3,…,n)为所述不动变焦系统中的n个光学元件的光焦度，e i(i＝1,2,3,…,n)为所述不动变焦系统中第i个光学元件和第i+1个光学元件之间的等效间隔，在所述不动变焦系统中的n个光学元件中，第m个和第n个光学元件是以形变器件分别作为两个光学组元，第1至第m-1个光学元件等效为一个光焦度为φ pre的光学组元，第m+1至第n-1个光学元件等效为一个光焦度为φ mid的光学组元，e' 1，e' 2和e' 3则是相邻两光学组元之间的等效间隔，同时，e' 4＝e n是所述不动变焦系统的后工作焦距。
- 根据权利要求3所述的高变倍比不动变焦成像方法，其特征在于，根据所述变焦方程提取出能够决定所述不动变焦系统的变倍比的关键参数包括：提取所述不动变焦系统的等效焦距的误差项A foc为：
其中，f表示所述不动变焦系统的等效焦距， 1C n为高斯常量；进一步地， 1C n＝[φ 1,-e 1,…,φ m,-e m,…,φ n]＝[φ pre,-e' 1,φ m,-e' 2,φ mid,-e' 3,φ n]。 - 根据权利要求3所述的高变倍比不动变焦成像方法，其特征在于，根据所述变焦方程提取出能够决定所述不动变焦系统的变倍比的关键参数还包括：提取所述不动变焦系统的系统离焦量的误差项A def为：
其中，Δφ m和Δφ n分别表示两个形变器件的光焦度变化量，Φ L表示所述不动变焦系统在长焦时的光焦度，Γ表示所述不动变焦系统的变倍比， 0B n、 0D n、 1A m分别为高斯常量；进一步地， 0B n＝[-e 0,φ 1,-e 1,…,φ n-1,-e n-1]， 0D n＝[-e 0,φ 1,-e 1,…,φ n-1,-e n-1,φ n]， 1A m＝[φ 1,-e 1,φ 2,-e 2,…,φ m-1,-e m-1]，e 0为所述不动变焦系统中物面和第1个光学元件之间的等效间隔。 - 根据权利要求1所述的高变倍比不动变焦成像方法，其特征在于，步骤S2中的所述不动变焦系统的初阶像差参数包括所述不动变焦系统的初阶球差、初阶像散和初阶畸变的误差项。
- 根据权利要求6所述的高变倍比不动变焦成像方法，其特征在于，所述不动变焦系统的初阶球差的误差项A spa为：
其中，所述不动变焦系统中包括n个光学元件，A j＝(u' j-u j)/(1/n j+1-1/n j)，u j和u' j分别表示第j个光学元件的边缘光线入射角和出射角，n j表示第j个光学元件后的折射率，h j表示第j个光学元件的边缘光线高度，c j表示第j个光学元件面形的顶点曲率，k j表示第j个光学元件面形的二次曲面常数。 - 根据权利要求6所述的高变倍比不动变焦成像方法，其特征在于，所述 不动变焦系统的初阶像散的误差项A ast为：
其中，所述不动变焦系统中包括n个光学元件，
A j＝(u' j-u j)/(1/n j+1-1/n j)；u j和u' j分别表示第j个光学元件的边缘光线入射角和出射角，n j表示第j个光学元件后的折射率，h j表示第j个光学元件的边缘光线高度，
表示第j个光学元件的中心光线高度，
和
分别表示第j个光学元件的中心光线入射角和出射角，c j表示第j个光学元件面形的顶点曲率，k j表示第j个光学元件面形的二次曲面常数，
为第j个光学元件的等效视场；
进一步地，表示归一化的视场向量，
表示第j个光学元件的视场偏移矢量。
- 根据权利要求6所述的高变倍比不动变焦成像方法，其特征在于，所述不动变焦系统的初阶畸变的误差项A dis为：
其中，所述不动变焦系统中包括n个光学元件，
A j＝(u' j-u j)/(1/n j+1-1/n j)；u j和u' j分别表示第j个光学元件的边缘光线入射角和出射角，n j表示第j个光学元件后的折射率，h j表示第j个光学元件的边缘光线高度，
表示第j个光学元件的中心光线高度，
和
分别表示第j个光学元件的中心光线入射角和出射角，c j表示第j个光学元件面形的顶点曲率，k j表示第j个光学元件面形的二次曲面常数，
为第j个光学元件的等效视场；
进一步地，表示归一化的视场向量，
表示第j个光学元件的视场偏移矢量。
- 根据权利要求1所述的高变倍比不动变焦成像方法，其特征在于，步骤S3建立的非线性全局评价函数为：
其中，所述不动变焦系统中包括n个光学元件，且第m个和第n个光学元件是形变器件，上标l表示所述不动变焦系统的第l个采样焦距点；M表示采样焦距点的数量；H k表示第k个采样视场点，N表示采样视场点的数量；e j表示第j个和第j+1个光学元件之间的等效间隔，α j表示第j个光学元件的倾斜角，c i和k i分别表示第i个光学元件面形的顶点曲率和二次曲面参数；c m和k m分别表示第m个光学元件面形的顶点曲率和二次曲面参数；c n和k n分别表示第n个光学元件面形的顶点曲率和二次曲面参数；ν i(i＝1,2,3,…)表示对应项的权重，A foc为所述不动变焦系统的等效焦距的误差项，A def为所述不动变焦系统的系统离焦量的误差项，A spa为所述不动变焦系统的初阶球差的误差项，A ast为所述不动变焦系统的初阶像散的误差项，A dis为所述不动变焦系统的初阶畸变的误差项，|| || 1表示1范数；
进一步地，步骤S3中采用全局优化算法来对所述非线性全局评价函数进行全局最优解检索，求解得到另所述非线性全局评价函数的数值最小的解集，根据该解集获得具有高变倍比的不动变焦系统。
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| CN115079406A (zh) * | 2022-07-06 | 2022-09-20 | 清华大学深圳国际研究生院 | 一种折反射式不动型反摄远变焦系统设计方法 |
| CN116540407A (zh) * | 2023-07-06 | 2023-08-04 | 中国科学院长春光学精密机械与物理研究所 | 低偏振像差三反光学系统设计方法、系统、设备及介质 |
| CN117194849B (zh) * | 2023-11-06 | 2024-01-12 | 中国科学院长春光学精密机械与物理研究所 | 基于矢量乘法的表面面形的误差求解方法 |
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| CN112558296B (zh) * | 2020-12-11 | 2022-09-09 | 清华大学深圳国际研究生院 | 一种应用形变器件的高变倍比不动变焦成像方法 |
| CN113406792B (zh) * | 2021-05-28 | 2022-08-26 | 清华大学深圳国际研究生院 | 一种不动型双远心变焦扫描成像系统及主结构参数确定方法 |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201397417Y (zh) * | 2008-08-26 | 2010-02-03 | 中国科学院西安光学精密机械研究所 | 一种实现无移动镜组变焦距光学系统 |
| US20180164572A1 (en) * | 2016-12-13 | 2018-06-14 | Thales | Compact telescope having a plurality of focal lengths compensated for by a deformable mirror |
| CN109946829A (zh) * | 2019-04-26 | 2019-06-28 | 北京理工大学 | 变焦稳像一体化成像系统中变形镜变焦面形设计方法 |
| CN110068924A (zh) * | 2019-04-19 | 2019-07-30 | 南京邮电大学 | 基于三层液体结构的非球面透镜的面型分析方法 |
| CN110133846A (zh) * | 2019-04-26 | 2019-08-16 | 北京理工大学 | 变焦稳像一体化成像系统中变形镜稳像面形的设计方法 |
| CN111240010A (zh) * | 2020-01-08 | 2020-06-05 | 北京理工大学 | 一种用于自由曲面测量的可变形镜面形设计方法及装置 |
| CN112558296A (zh) * | 2020-12-11 | 2021-03-26 | 清华大学深圳国际研究生院 | 一种应用形变器件的高变倍比不动变焦成像方法 |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014138974A1 (en) * | 2013-03-15 | 2014-09-18 | Lensvector Inc. | Methods and apparatus for focus improvement in multiple liquid crystal cell lenses |
| US20150145958A1 (en) * | 2013-11-22 | 2015-05-28 | Canon Kabushiki Kaisha | Multi-lens image capturing apparatus |
| SG11202004547TA (en) * | 2017-12-28 | 2020-06-29 | Univ Brussel Vrije | Optical design methods for imaging systems and optical systems designed therewith |
-
2020
- 2020-12-11 CN CN202011458588.7A patent/CN112558296B/zh active Active
-
2021
- 2021-03-30 WO PCT/CN2021/083737 patent/WO2022121173A1/zh active Application Filing
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201397417Y (zh) * | 2008-08-26 | 2010-02-03 | 中国科学院西安光学精密机械研究所 | 一种实现无移动镜组变焦距光学系统 |
| US20180164572A1 (en) * | 2016-12-13 | 2018-06-14 | Thales | Compact telescope having a plurality of focal lengths compensated for by a deformable mirror |
| CN110068924A (zh) * | 2019-04-19 | 2019-07-30 | 南京邮电大学 | 基于三层液体结构的非球面透镜的面型分析方法 |
| CN109946829A (zh) * | 2019-04-26 | 2019-06-28 | 北京理工大学 | 变焦稳像一体化成像系统中变形镜变焦面形设计方法 |
| CN110133846A (zh) * | 2019-04-26 | 2019-08-16 | 北京理工大学 | 变焦稳像一体化成像系统中变形镜稳像面形的设计方法 |
| CN111240010A (zh) * | 2020-01-08 | 2020-06-05 | 北京理工大学 | 一种用于自由曲面测量的可变形镜面形设计方法及装置 |
| CN112558296A (zh) * | 2020-12-11 | 2021-03-26 | 清华大学深圳国际研究生院 | 一种应用形变器件的高变倍比不动变焦成像方法 |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115079406A (zh) * | 2022-07-06 | 2022-09-20 | 清华大学深圳国际研究生院 | 一种折反射式不动型反摄远变焦系统设计方法 |
| CN115079406B (zh) * | 2022-07-06 | 2023-09-01 | 清华大学深圳国际研究生院 | 一种折反射式不动型反摄远变焦系统设计方法 |
| CN116540407A (zh) * | 2023-07-06 | 2023-08-04 | 中国科学院长春光学精密机械与物理研究所 | 低偏振像差三反光学系统设计方法、系统、设备及介质 |
| CN116540407B (zh) * | 2023-07-06 | 2023-09-22 | 中国科学院长春光学精密机械与物理研究所 | 低偏振像差三反光学系统设计方法、系统、设备及介质 |
| CN117194849B (zh) * | 2023-11-06 | 2024-01-12 | 中国科学院长春光学精密机械与物理研究所 | 基于矢量乘法的表面面形的误差求解方法 |
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